1. What is an atom?
An atom is the smallest unit of an element.
2. Why is an atom electrically neutral?
An atom has equal numbers of protons and electrons.
3. What is a molecule?
A molecule is a group of atoms bonded together.
4. Why is oxygen a diatomic molecule?
Oxygen exists as O₂ with two atoms bonded.
5. What is the law of conservation of mass?
Mass of reactants equals mass of products.
6. Why does burning wood follow the law of conservation of mass?
Total mass of ash and gases equals wood’s mass.
7. What is the law of constant proportions?
A compound has elements in a fixed ratio.
8. Why does water always have the same composition?
Water has hydrogen and oxygen in a 2:1 ratio.
9. What is atomic mass?
Atomic mass is the mass of an atom in amu.
10. Why is carbon’s atomic mass 12 amu?
Carbon-12 is the standard for atomic mass.
11. What is a molecule of an element?
A molecule of an element contains identical atoms.
12. Why is nitrogen a molecule of an element?
Nitrogen exists as N₂ with two nitrogen atoms.
13. What is a molecule of a compound?
A molecule of a compound contains different atoms.
14. Why is carbon dioxide a molecule of a compound?
Carbon dioxide has one carbon and two oxygen atoms.
15. What is atomicity?
Atomicity is the number of atoms in a molecule.
16. Why is ozone’s atomicity 3?
Ozone exists as O₃ with three oxygen atoms.
17. What is the molecular mass?
Molecular mass is the sum of atomic masses in a molecule.
18. Why is water’s molecular mass 18 amu?
Water has two hydrogens (2 amu) and one oxygen (16 amu).
19. What is a mole?
A mole is 6.022 × 10²³ particles of a substance.
20. Why is a mole important in chemistry?
A mole relates mass to the number of particles.
21. What is Avogadro’s number?
Avogadro’s number is 6.022 × 10²³ particles per mole.
22. Why is Avogadro’s number used?
It counts particles in one mole of a substance.
23. What is molar mass?
Molar mass is the mass of one mole in grams.
24. Why is carbon dioxide’s molar mass 44 g/mol?
Carbon (12 g) plus two oxygens (32 g) equals 44 g.
25. What is a chemical formula?
A chemical formula shows the composition of a compound.
26. Why is NaCl the formula for sodium chloride?
NaCl shows one sodium and one chlorine atom.
27. What is a monoatomic molecule?
A monoatomic molecule has one atom.
28. Why is helium a monoatomic molecule?
Helium exists as single atoms, He.
29. What is a diatomic molecule?
A diatomic molecule has two atoms.
30. Why is hydrogen a diatomic molecule?
Hydrogen exists as H₂ with two atoms.
31. What is a triatomic molecule?
A triatomic molecule has three atoms.
32. Why is water a triatomic molecule?
Water has two hydrogens and one oxygen atom.
33. What is a polyatomic molecule?
A polyatomic molecule has more than two atoms.
34. Why is methane a polyatomic molecule?
Methane has one carbon and four hydrogen atoms.
35. What is the atomic mass of hydrogen?
The atomic mass of hydrogen is 1 amu.
36. Why is oxygen’s atomic mass 16 amu?
Oxygen’s atomic mass is based on its nucleus.
37. What is the molecular mass of oxygen gas?
The molecular mass of O₂ is 32 amu.
38. Why is nitrogen gas’s molecular mass 28 amu?
Nitrogen gas (N₂) has two nitrogens (14 amu each).
39. What is a cation?
A cation is a positively charged ion.
40. Why is Na⁺ a cation?
Na⁺ has lost one electron, gaining a positive charge.
41. What is an anion?
An anion is a negatively charged ion.
42. Why is Cl⁻ an anion?
Cl⁻ has gained one electron, gaining a negative charge.
43. What is an ion?
An ion is an atom with a charge.
44. Why do atoms form ions?
Atoms gain or lose electrons to become stable.
45. What is the formula of carbon dioxide?
The formula of carbon dioxide is CO₂.
46. Why is CO₂ a compound?
CO₂ has carbon and oxygen chemically bonded.
47. What is the molar mass of water?
The molar mass of water is 18 g/mol.
48. Why is ammonia’s molar mass 17 g/mol?
Ammonia has one nitrogen (14 g) and three hydrogens (3 g).
49. What is the atomicity of sulfur?
The atomicity of sulfur is 8 (S₈).
50. Why is phosphorus’s atomicity 4?
Phosphorus exists as P₄ with four atoms.
51. What is a chemical equation?
A chemical equation shows reactants and products.
52. Why is H₂ + O₂ → H₂O a chemical equation?
It shows hydrogen and oxygen forming water.
53. What is the law of chemical combination?
Elements combine in fixed ratios to form compounds.
54. Why do compounds follow definite proportions?
Compounds have a fixed ratio of elements by mass.
55. What is the atomic mass of nitrogen?
The atomic mass of nitrogen is 14 amu.
56. Why is chlorine’s atomic mass 35.5 amu?
Chlorine’s atomic mass is an average of its isotopes.
57. What is the molecular mass of ammonia?
The molecular mass of ammonia is 17 amu.
58. Why is methane’s molecular mass 16 amu?
Methane has one carbon (12 amu) and four hydrogens (4 amu).
59. What is a mole of oxygen gas?
A mole of oxygen gas is 32 grams of O₂.
60. Why is a mole of water 18 grams?
Water’s molar mass is 18 g/mol.
61. What is the number of particles in one mole?
One mole contains 6.022 × 10²³ particles.
62. Why is Avogadro’s number constant?
It defines the number of particles in a mole.
63. What is the formula of sodium chloride?
The formula of sodium chloride is NaCl.
64. Why is CaCO₃ the formula of calcium carbonate?
CaCO₃ shows one calcium, one carbon, three oxygens.
65. What is the atomicity of hydrogen gas?
The atomicity of hydrogen gas is 2.
66. Why is oxygen gas’s atomicity 2?
Oxygen gas exists as O₂ with two atoms.
67. What is the molar mass of sodium chloride?
The molar mass of sodium chloride is 58.5 g/mol.
68. Why is glucose’s molar mass 180 g/mol?
Glucose has 6 carbons, 12 hydrogens, 6 oxygens.
69. What is a polyatomic ion?
A polyatomic ion is a charged group of atoms.
70. Why is NH₄⁺ a polyatomic ion?
NH₄⁺ is a charged group of nitrogen and hydrogens.
71. What is the atomic mass of sodium?
The atomic mass of sodium is 23 amu.
72. Why is calcium’s atomic mass 40 amu?
Calcium’s atomic mass is based on its nucleus.
73. What is the molecular mass of carbon dioxide?
The molecular mass of carbon dioxide is 44 amu.
74. Why is ethanol’s molecular mass 46 amu?
Ethanol has 2 carbons, 6 hydrogens, 1 oxygen.
75. What is a mole of carbon?
A mole of carbon is 12 grams of C.
76. Why is a mole of sodium 23 grams?
Sodium’s molar mass is 23 g/mol.
77. What is the formula of ammonia?
The formula of ammonia is NH₃.
78. Why is CH₄ the formula of methane?
CH₄ shows one carbon and four hydrogen atoms.
79. What is the atomicity of carbon dioxide?
The atomicity of carbon dioxide is 3.
80. Why is ammonia’s atomicity 4?
Ammonia has one nitrogen and three hydrogen atoms.
81. What is the molar mass of methane?
The molar mass of methane is 16 g/mol.
82. Why is sulfuric acid’s molar mass 98 g/mol?
Sulfuric acid has 2 hydrogens, 1 sulfur, 4 oxygens.
83. What is a chemical symbol?
A chemical symbol represents an element.
84. Why is O the symbol for oxygen?
O is a shorthand for oxygen on the periodic table.
85. What is the atomic mass of sulfur?
The atomic mass of sulfur is 32 amu.
86. Why is magnesium’s atomic mass 24 amu?
Magnesium’s atomic mass is based on its nucleus.
87. What is the molecular mass of nitrogen gas?
The molecular mass of nitrogen gas is 28 amu.
88. Why is hydrochloric acid’s molecular mass 36.5 amu?
HCl has one hydrogen (1 amu) and one chlorine (35.5 amu).
89. What is a mole of nitrogen gas?
A mole of nitrogen gas is 28 grams of N₂.
90. Why is a mole of oxygen 16 grams?
Oxygen’s molar mass is 16 g/mol for one atom.
91. What is the formula of glucose?
The formula of glucose is C₆H₁₂O₆.
92. Why is H₂SO₄ the formula of sulfuric acid?
H₂SO₄ shows 2 hydrogens, 1 sulfur, 4 oxygens.
93. What is the atomicity of methane?
The atomicity of methane is 5.
94. Why is carbon dioxide’s atomicity 3?
95. What is the molar mass of ammonia?
The molar mass of ammonia is 17 g/mol.
96. Why is ethanol’s molar mass 46 g/mol?
97. What is a valence electron?
A valence electron is in an atom’s outermost shell.
98. Why do valence electrons form bonds?
Valence electrons help atoms achieve stability.
99. What is the atomic mass of phosphorus?
The atomic mass of phosphorus is 31 amu.
100. Why is potassium’s atomic mass 39 amu?
Potassium’s atomic mass is based on its nucleus.
101. What is the molecular mass of sulfur dioxide?
The molecular mass of sulfur dioxide is 64 amu.
102. Why is nitric acid’s molecular mass 63 amu?
Nitric acid has 1 hydrogen, 1 nitrogen, 3 oxygens.
103. What is a mole of sulfur?
A mole of sulfur is 32 grams of S.
104. Why is a mole of chlorine 35.5 grams?
Chlorine’s molar mass is 35.5 g/mol for one atom.
105. What is the formula of sodium hydroxide?
The formula of sodium hydroxide is NaOH.
106. Why is CaCl₂ the formula of calcium chloride?
CaCl₂ shows one calcium and two chlorine atoms.
107. What is the atomicity of sulfur dioxide?
The atomicity of sulfur dioxide is 3.
108. Why is glucose’s atomicity 24?
109. What is the molar mass of carbon dioxide?
The molar mass of carbon dioxide is 44 g/mol.
110. Why is sodium bicarbonate’s molar mass 84 g/mol?
NaHCO₃ has 1 sodium, 1 hydrogen, 1 carbon, 3 oxygens.
111. What is a chemical bond?
A chemical bond holds atoms together in a molecule.
112. Why do atoms form chemical bonds?
Atoms bond to achieve a stable electron configuration.
113. What is the atomic mass of iron?
The atomic mass of iron is 56 amu.
114. Why is aluminum’s atomic mass 27 amu?
Aluminum’s atomic mass is based on its nucleus.
115. What is the molecular mass of hydrogen chloride?
The molecular mass of hydrogen chloride is 36.5 amu.
116. Why is acetic acid’s molecular mass 60 amu?
Acetic acid has 2 carbons, 4 hydrogens, 2 oxygens.
117. What is a mole of iron?
A mole of iron is 56 grams of Fe.
118. Why is a mole of aluminum 27 grams?
Aluminum’s molar mass is 27 g/mol.
119. What is the formula of magnesium oxide?
The formula of magnesium oxide is MgO.
120. Why is KCl the formula of potassium chloride?
KCl shows one potassium and one chlorine atom.
121. What is the atomicity of sodium chloride?
The atomicity of sodium chloride is 2.
122. Why is sulfuric acid’s atomicity 7?
123. What is the molar mass of glucose?
The molar mass of glucose is 180 g/mol.
124. Why is urea’s molar mass 60 g/mol?
Urea has 1 carbon, 2 nitrogens, 4 hydrogens, 1 oxygen.
125. What is a molecule’s stability due to?
A molecule’s stability is due to chemical bonds.
126. Why is O₂ stable?
O₂ has a strong double bond between oxygen atoms.
127. What is the atomic mass of copper?
The atomic mass of copper is 63.5 amu.
128. Why is zinc’s atomic mass 65 amu?
Zinc’s atomic mass is based on its isotopes.
129. What is the molecular mass of carbon monoxide?
The molecular mass of carbon monoxide is 28 amu.
130. Why is benzene’s molecular mass 78 amu?
Benzene has 6 carbons and 6 hydrogens.
131. What is a mole of copper?
A mole of copper is 63.5 grams of Cu.
132. Why is a mole of zinc 65 grams?
Zinc’s molar mass is 65 g/mol.
133. What is the formula of aluminum oxide?
The formula of aluminum oxide is Al₂O₃.
134. Why is Na₂CO₃ the formula of sodium carbonate?
Na₂CO₃ shows 2 sodiums, 1 carbon, 3 oxygens.
135. What is the atomicity of ammonia?
The atomicity of ammonia is 4.
136. Why is ethanol’s atomicity 9?
137. What is the molar mass of sulfur dioxide?
The molar mass of sulfur dioxide is 64 g/mol.
138. Why is calcium carbonate’s molar mass 100 g/mol?
CaCO₃ has 1 calcium, 1 carbon, 3 oxygens.
139. What is a proton?
A proton is a positively charged particle in the nucleus.
140. Why do protons determine an element?
The number of protons defines the atomic number.
141. What is the atomic mass of silver?
The atomic mass of silver is 108 amu.
142. Why is gold’s atomic mass 197 amu?
Gold’s atomic mass is based on its nucleus.
143. What is the molecular mass of hydrogen sulfide?
The molecular mass of hydrogen sulfide is 34 amu.
144. Why is glycerol’s molecular mass 92 amu?
Glycerol has 3 carbons, 8 hydrogens, 3 oxygens.
145. What is a mole of silver?
A mole of silver is 108 grams of Ag.
146. Why is a mole of gold 197 grams?
Gold’s molar mass is 197 g/mol.
147. What is the formula of potassium hydroxide?
The formula of potassium hydroxide is KOH.
148. Why is MgCl₂ the formula of magnesium chloride?
MgCl₂ shows one magnesium and two chlorine atoms.
149. What is the atomicity of carbon monoxide?
The atomicity of carbon monoxide is 2.
150. Why is glucose’s atomicity 24?
151. What is the molar mass of hydrogen chloride?
The molar mass of hydrogen chloride is 36.5 g/mol.
152. Why is sodium sulfate’s molar mass 142 g/mol?
Na₂SO₄ has 2 sodiums, 1 sulfur, 4 oxygens.
153. What is an electron?
An electron is a negatively charged particle.
154. Why do electrons balance protons?
Electrons equal protons in a neutral atom.
155. What is the atomic mass of lead?
The atomic mass of lead is 207 amu.
156. Why is tin’s atomic mass 119 amu?
Tin’s atomic mass is based on its isotopes.
157. What is the molecular mass of sulfur trioxide?
The molecular mass of sulfur trioxide is 80 amu.
158. Why is sucrose’s molecular mass 342 amu?
Sucrose has 12 carbons, 22 hydrogens, 11 oxygens.
159. What is a mole of lead?
A mole of lead is 207 grams of Pb.
160. Why is a mole of tin 119 grams?
Tin’s molar mass is 119 g/mol.
161. What is the formula of sodium bicarbonate?
The formula of sodium bicarbonate is NaHCO₃.
162. Why is Fe₂O₃ the formula of iron(III) oxide?
Fe₂O₃ shows two irons and three oxygens.
163. What is the atomicity of hydrogen sulfide?
The atomicity of hydrogen sulfide is 3.
164. Why is benzene’s atomicity 12?
165. What is the molar mass of carbon monoxide?
The molar mass of carbon monoxide is 28 g/mol.
166. Why is ammonium chloride’s molar mass 53.5 g/mol?
NH₄Cl has 1 nitrogen, 4 hydrogens, 1 chlorine.
167. What is a neutron?
A neutron is a neutral particle in the nucleus.
168. Why do neutrons affect mass?
Neutrons add to an atom’s mass but not charge.
169. What is the atomic mass of mercury?
The atomic mass of mercury is 201 amu.
170. Why is nickel’s atomic mass 59 amu?
Nickel’s atomic mass is based on its isotopes.
171. What is the molecular mass of nitrous oxide?
The molecular mass of nitrous oxide is 44 amu.
172. Why is fructose’s molecular mass 180 amu?
Fructose has 6 carbons, 12 hydrogens, 6 oxygens.
173. What is a mole of mercury?
A mole of mercury is 201 grams of Hg.
174. Why is a mole of nickel 59 grams?
Nickel’s molar mass is 59 g/mol.
175. What is the formula of calcium hydroxide?
The formula of calcium hydroxide is Ca(OH)₂.
176. Why is ZnSO₄ the formula of zinc sulfate?
ZnSO₄ shows one zinc, one sulfur, four oxygens.
177. What is the atomicity of sulfur trioxide?
The atomicity of sulfur trioxide is 4.
178. Why is sucrose’s atomicity 45?
179. What is the molar mass of nitrous oxide?
The molar mass of nitrous oxide is 44 g/mol.
180. Why is potassium nitrate’s molar mass 101 g/mol?
KNO₃ has 1 potassium, 1 nitrogen, 3 oxygens.
181. What is an isotope?
An isotope has the same protons but different neutrons.
182. Why is carbon-14 an isotope?
Carbon-14 has two more neutrons than carbon-12.
183. What is the atomic mass of chromium?
The atomic mass of chromium is 52 amu.
184. Why is manganese’s atomic mass 55 amu?
Manganese’s atomic mass is based on its nucleus.
185. What is the molecular mass of phosphorus pentoxide?
The molecular mass of phosphorus pentoxide is 142 amu.
186. Why is lactose’s molecular mass 342 amu?
Lactose has 12 carbons, 22 hydrogens, 11 oxygens.
187. What is a mole of chromium?
A mole of chromium is 52 grams of Cr.
188. Why is a mole of manganese 55 grams?
Manganese’s molar mass is 55 g/mol.
189. What is the formula of ammonium sulfate?
The formula of ammonium sulfate is (NH₄)₂SO₄.
190. Why is CuSO₄ the formula of copper sulfate?
CuSO₄ shows one copper, one sulfur, four oxygens.
191. What is the atomicity of nitrous oxide?
The atomicity of nitrous oxide is 3.
192. Why is fructose’s atomicity 24?
193. What is the molar mass of phosphorus pentoxide?
The molar mass of phosphorus pentoxide is 142 g/mol.
194. Why is sodium phosphate’s molar mass 164 g/mol?
Na₃PO₄ has 3 sodiums, 1 phosphorus, 4 oxygens.
195. What is an atomic number?
An atomic number is the number of protons.
196. Why does atomic number define an element?
Each element has a unique number of protons.
197. What is the atomic mass of cobalt?
The atomic mass of cobalt is 59 amu.
198. Why is vanadium’s atomic mass 51 amu?
Vanadium’s atomic mass is based on its nucleus.
199. What is the molecular mass of dinitrogen pentoxide?
The molecular mass of dinitrogen pentoxide is 108 amu.
200. Why is maltose’s molecular mass 342 amu?
Maltose has 12 carbons, 22 hydrogens, 11 oxygens.
201. What is a mole of cobalt?
A mole of cobalt is 59 grams of Co.
202. Why is a mole of vanadium 51 grams?
Vanadium’s molar mass is 51 g/mol.
203. What is the formula of barium chloride?
The formula of barium chloride is BaCl₂.
204. Why is NaNO₃ the formula of sodium nitrate?
NaNO₃ shows one sodium, one nitrogen, three oxygens.
205. What is the atomicity of dinitrogen pentoxide?
The atomicity of dinitrogen pentoxide is 7.
206. Why is lactose’s atomicity 45?
207. What is the molar mass of dinitrogen pentoxide?
The molar mass of dinitrogen pentoxide is 108 g/mol.
208. Why is calcium phosphate’s molar mass 310 g/mol?
Ca₃(PO₄)₂ has 3 calciums, 2 phosphorus, 8 oxygens.
209. What is a mass number?
A mass number is protons plus neutrons.
210. Why does mass number vary in isotopes?
Isotopes have different numbers of neutrons.
211. What is the atomic mass of titanium?
The atomic mass of titanium is 48 amu.
212. Why is scandium’s atomic mass 45 amu?
Scandium’s atomic mass is based on its nucleus.
213. What is the molecular mass of chlorine gas?
The molecular mass of chlorine gas is 71 amu.
214. Why is citric acid’s molecular mass 192 amu?
Citric acid has 6 carbons, 8 hydrogens, 7 oxygens.
215. What is a mole of titanium?
A mole of titanium is 48 grams of Ti.
216. Why is a mole of scandium 45 grams?
Scandium’s molar mass is 45 g/mol.
217. What is the formula of potassium carbonate?
The formula of potassium carbonate is K₂CO₃.
218. Why is FeCl₃ the formula of iron(III) chloride?
FeCl₃ shows one iron and three chlorine atoms.
219. What is the atomicity of chlorine gas?
The atomicity of chlorine gas is 2.
220. Why is citric acid’s atomicity 21?
221. What is the molar mass of chlorine gas?
The molar mass of chlorine gas is 71 g/mol.
222. Why is ammonium nitrate’s molar mass 80 g/mol?
NH₄NO₃ has 2 nitrogens, 4 hydrogens, 3 oxygens.
223. What is a molecule’s composition?
A molecule’s composition is its atoms and their ratio.
224. Why does water have a fixed composition?
Water always has two hydrogens and one oxygen.
225. What is the atomic mass of barium?
The atomic mass of barium is 137 amu.
226. Why is strontium’s atomic mass 88 amu?
Strontium’s atomic mass is based on its nucleus.
227. What is the molecular mass of iodine gas?
The molecular mass of iodine gas is 254 amu.
228. Why is oxalic acid’s molecular mass 90 amu?
Oxalic acid has 2 carbons, 2 hydrogens, 4 oxygens.
229. What is a mole of barium?
A mole of barium is 137 grams of Ba.
230. Why is a mole of strontium 88 grams?
Strontium’s molar mass is 88 g/mol.
231. What is the formula of sodium sulfate?
The formula of sodium sulfate is Na₂SO₄.
232. Why is AlCl₃ the formula of aluminum chloride?
AlCl₃ shows one aluminum and three chlorine atoms.
233. What is the atomicity of iodine gas?
The atomicity of iodine gas is 2.
234. Why is oxalic acid’s atomicity 8?
235. What is the molar mass of iodine gas?
The molar mass of iodine gas is 254 g/mol.
236. Why is potassium chloride’s molar mass 74.5 g/mol?
KCl has 1 potassium and 1 chlorine.
237. What is a molecule’s bond type?
A molecule’s bond type can be covalent or ionic.
238. Why is NaCl ionic?
NaCl forms from electron transfer between sodium and chlorine.
239. What is the atomic mass of iodine?
The atomic mass of iodine is 127 amu.
240. Why is bromine’s atomic mass 80 amu?
Bromine’s atomic mass is based on its isotopes.
241. What is the molecular mass of bromine gas?
The molecular mass of bromine gas is 160 amu.
242. Why is tartaric acid’s molecular mass 150 amu?
Tartaric acid has 4 carbons, 6 hydrogens, 6 oxygens.
243. What is a mole of iodine?
A mole of iodine is 127 grams of I.
244. Why is a mole of bromine 80 grams?
Bromine’s molar mass is 80 g/mol for one atom.
245. What is the formula of calcium carbonate?
The formula of calcium carbonate is CaCO₃.
246. Why is NaBr the formula of sodium bromide?
NaBr shows one sodium and one bromine atom.
247. What is the atomicity of bromine gas?
The atomicity of bromine gas is 2.
248. Why is tartaric acid’s atomicity 16?
249. What is the molar mass of bromine gas?
The molar mass of bromine gas is 160 g/mol.
250. Why is magnesium sulfate’s molar mass 120 g/mol?
MgSO₄ has 1 magnesium, 1 sulfur, 4 oxygens.
251. What is a covalent bond?
A covalent bond shares electrons between atoms.
252. Why is H₂O covalent?
Water shares electrons between hydrogen and oxygen.
253. What is the atomic mass of fluorine?
The atomic mass of fluorine is 19 amu.
254. Why is neon’s atomic mass 20 amu?
Neon’s atomic mass is based on its nucleus.
255. What is the molecular mass of fluorine gas?
The molecular mass of fluorine gas is 38 amu.
256. Why is urea’s molecular mass 60 amu?
257. What is a mole of fluorine?
A mole of fluorine is 19 grams of F.
258. Why is a mole of neon 20 grams?
Neon’s molar mass is 20 g/mol.
259. What is the formula of potassium bromide?
The formula of potassium bromide is KBr.
260. Why is CaSO₄ the formula of calcium sulfate?
CaSO₄ shows one calcium, one sulfur, four oxygens.
261. What is the atomicity of fluorine gas?
The atomicity of fluorine gas is 2.
262. Why is urea’s atomicity 8?
263. What is the molar mass of fluorine gas?
The molar mass of fluorine gas is 38 g/mol.
264. Why is sodium acetate’s molar mass 82 g/mol?
NaC₂H₃O₂ has 1 sodium, 2 carbons, 3 hydrogens, 2 oxygens.
265. What is an ionic bond?
An ionic bond forms by electron transfer.
266. Why is KCl ionic?
KCl forms from electron transfer between potassium and chlorine.
267. What is the atomic mass of argon?
The atomic mass of argon is 40 amu.
268. Why is krypton’s atomic mass 84 amu?
Krypton’s atomic mass is based on its isotopes.
269. What is the molecular mass of neon gas?
The molecular mass of neon gas is 20 amu.
270. Why is aspirin’s molecular mass 180 amu?
Aspirin has 9 carbons, 8 hydrogens, 4 oxygens.
271. What is a mole of argon?
A mole of argon is 40 grams of Ar.
272. Why is a mole of krypton 84 grams?
Krypton’s molar mass is 84 g/mol.
273. What is the formula of sodium phosphate?
The formula of sodium phosphate is Na₃PO₄.
274. Why is MgSO₄ the formula of magnesium sulfate?
MgSO₄ shows one magnesium, one sulfur, four oxygens.
275. What is the atomicity of neon gas?
The atomicity of neon gas is 1.
276. Why is aspirin’s atomicity 21?
277. What is the molar mass of neon gas?
The molar mass of neon gas is 20 g/mol.
278. Why is calcium nitrate’s molar mass 164 g/mol?
Ca(NO₃)₂ has 1 calcium, 2 nitrogens, 6 oxygens.
279. What is a molecule’s energy?
A molecule’s energy is stored in its bonds.
280. Why do molecules vibrate?
Molecules vibrate due to thermal energy.
281. What is the atomic mass of xenon?
The atomic mass of xenon is 131 amu.
282. Why is radon’s atomic mass 222 amu?
Radon’s atomic mass is based on its nucleus.
283. What is the molecular mass of argon gas?
The molecular mass of argon gas is 40 amu.
284. Why is ethanol’s molecular mass 46 amu?
285. What is a mole of xenon?
A mole of xenon is 131 grams of Xe.
286. Why is a mole of radon 222 grams?
Radon’s molar mass is 222 g/mol.
287. What is the formula of ammonium chloride?
The formula of ammonium chloride is NH₄Cl.
288. Why is BaSO₄ the formula of barium sulfate?
BaSO₄ shows one barium, one sulfur, four oxygens.
289. What is the atomicity of argon gas?
The atomicity of argon gas is 1.
290. Why is ethanol’s atomicity 9?
291. What is the molar mass of argon gas?
The molar mass of argon gas is 40 g/mol.
292. Why is potassium sulfate’s molar mass 174 g/mol?
K₂SO₄ has 2 potassiums, 1 sulfur, 4 oxygens.
293. What is a molecule’s shape?
A molecule’s shape depends on its bond angles.
294. Why is water bent?
Water’s oxygen has lone pairs affecting bond angles.
295. What is the atomic mass of lithium?
The atomic mass of lithium is 7 amu.
296. Why is beryllium’s atomic mass 9 amu?
Beryllium’s atomic mass is based on its nucleus.
297. What is the molecular mass of lithium hydride?
The molecular mass of lithium hydride is 8 amu.
298. Why is methanol’s molecular mass 32 amu?
Methanol has 1 carbon, 4 hydrogens, 1 oxygen.
299. What is a mole of lithium?
A mole of lithium is 7 grams of Li.
300. Why is a mole of beryllium 9 grams?
Beryllium’s molar mass is 9 g/mol.
301. What is the formula of lithium chloride?
The formula of lithium chloride is LiCl.
302. Why is Na₂SO₄ the formula of sodium sulfate?
Na₂SO₄ shows 2 sodiums, 1 sulfur, 4 oxygens.
303. What is the atomicity of lithium hydride?
The atomicity of lithium hydride is 2.
304. Why is methanol’s atomicity 6?
305. What is the molar mass of lithium hydride?
The molar mass of lithium hydride is 8 g/mol.
306. Why is ammonium sulfate’s molar mass 132 g/mol?
(NH₄)₂SO₄ has 2 nitrogens, 8 hydrogens, 1 sulfur, 4 oxygens.
307. What is a molecule’s polarity?
A molecule’s polarity depends on electron distribution.
308. Why is water polar?
Water’s oxygen pulls electrons more than hydrogen.
309. What is the atomic mass of boron?
The atomic mass of boron is 11 amu.
310. Why is silicon’s atomic mass 28 amu?
Silicon’s atomic mass is based on its isotopes.
311. What is the molecular mass of boric acid?
The molecular mass of boric acid is 62 amu.
312. Why is propanol’s molecular mass 60 amu?
Propanol has 3 carbons, 8 hydrogens, 1 oxygen.
313. What is a mole of boron?
A mole of boron is 11 grams of B.
314. Why is a mole of silicon 28 grams?
Silicon’s molar mass is 28 g/mol.
315. What is the formula of boric acid?
The formula of boric acid is H₃BO₃.
316. Why is KNO₃ the formula of potassium nitrate?
KNO₃ shows one potassium, one nitrogen, three oxygens.
317. What is the atomicity of boric acid?
The atomicity of boric acid is 7.
318. Why is propanol’s atomicity 12?
319. What is the molar mass of boric acid?
The molar mass of boric acid is 62 g/mol.
320. Why is calcium chloride’s molar mass 111 g/mol?
CaCl₂ has 1 calcium and 2 chlorines.
321. What is a molecule’s reactivity?
A molecule’s reactivity depends on its bonds and structure.
322. Why is methane less reactive?
Methane has strong carbon-hydrogen bonds.
323. What is the atomic mass of arsenic?
The atomic mass of arsenic is 75 amu.
324. Why is selenium’s atomic mass 79 amu?
Selenium’s atomic mass is based on its isotopes.
325. What is the molecular mass of arsenic trioxide?
The molecular mass of arsenic trioxide is 198 amu.
326. Why is butanol’s molecular mass 74 amu?
Butanol has 4 carbons, 10 hydrogens, 1 oxygen.
327. What is a mole of arsenic?
A mole of arsenic is 75 grams of As.
328. Why is a mole of selenium 79 grams?
Selenium’s molar mass is 79 g/mol.
329. What is the formula of arsenic trioxide?
The formula of arsenic trioxide is As₂O₃.
330. Why is NaCl the formula of sodium chloride?
331. What is the atomicity of arsenic trioxide?
The atomicity of arsenic trioxide is 5.
332. Why is butanol’s atomicity 15?
333. What is the molar mass of arsenic trioxide?
The molar mass of arsenic trioxide is 198 g/mol.
334. Why is barium chloride’s molar mass 208 g/mol?
BaCl₂ has 1 barium and 2 chlorines.
335. What is a molecule’s bond energy?
A molecule’s bond energy is needed to break its bonds.
336. Why is N₂ stable?
N₂ has a strong triple bond.
337. What is the atomic mass of antimony?
The atomic mass of antimony is 122 amu.
338. Why is tellurium’s atomic mass 128 amu?
Tellurium’s atomic mass is based on its isotopes.
339. What is the molecular mass of antimony trioxide?
The molecular mass of antimony trioxide is 292 amu.
340. Why is pentanol’s molecular mass 88 amu?
Pentanol has 5 carbons, 12 hydrogens, 1 oxygen.
341. What is a mole of antimony?
A mole of antimony is 122 grams of Sb.
342. Why is a mole of tellurium 128 grams?
Tellurium’s molar mass is 128 g/mol.
343. What is the formula of antimony trioxide?
The formula of antimony trioxide is Sb₂O₃.
344. Why is KBr the formula of potassium bromide?
KBr shows one potassium and one bromine atom.
345. What is the atomicity of antimony trioxide?
The atomicity of antimony trioxide is 5.
346. Why is pentanol’s atomicity 18?
347. What is the molar mass of antimony trioxide?
The molar mass of antimony trioxide is 292 g/mol.
348. Why is sodium bromide’s molar mass 103 g/mol?
NaBr has 1 sodium and 1 bromine.
349. What is a molecule’s bond length?
A molecule’s bond length is the distance between nuclei.
350. Why is O₂’s bond shorter than Cl₂’s?
O₂ has a double bond, stronger than Cl₂’s single bond.
351. What is the atomic mass of bismuth?
The atomic mass of bismuth is 209 amu.
352. Why is polonium’s atomic mass 209 amu?
Polonium’s atomic mass is based on its nucleus.
353. What is the molecular mass of bismuth trioxide?
The molecular mass of bismuth trioxide is 466 amu.
354. Why is hexanol’s molecular mass 102 amu?
Hexanol has 6 carbons, 14 hydrogens, 1 oxygen.
355. What is a mole of bismuth?
A mole of bismuth is 209 grams of Bi.
356. Why is a mole of polonium 209 grams?
Polonium’s molar mass is 209 g/mol.
357. What is the formula of bismuth trioxide?
The formula of bismuth trioxide is Bi₂O₃.
358. Why is LiCl the formula of lithium chloride?
LiCl shows one lithium and one chlorine atom.
359. What is the atomicity of bismuth trioxide?
The atomicity of bismuth trioxide is 5.
360. Why is hexanol’s atomicity 21?
361. What is the molar mass of bismuth trioxide?
The molar mass of bismuth trioxide is 466 g/mol.
362. Why is potassium iodide’s molar mass 166 g/mol?
KI has 1 potassium and 1 iodine.
363. What is a molecule’s dipole moment?
A molecule’s dipole moment measures its polarity.
364. Why is HCl polar?
Chlorine pulls electrons more than hydrogen.
365. What is the atomic mass of cesium?
The atomic mass of cesium is 133 amu.
366. Why is rubidium’s atomic mass 85 amu?
Rubidium’s atomic mass is based on its isotopes.
367. What is the molecular mass of cesium chloride?
The molecular mass of cesium chloride is 168.5 amu.
368. Why is heptanol’s molecular mass 116 amu?
Heptanol has 7 carbons, 16 hydrogens, 1 oxygen.
369. What is a mole of cesium?
A mole of cesium is 133 grams of Cs.
370. Why is a mole of rubidium 85 grams?
Rubidium’s molar mass is 85 g/mol.
371. What is the formula of cesium chloride?
The formula of cesium chloride is CsCl.
372. Why is NaI the formula of sodium iodide?
NaI shows one sodium and one iodine atom.
373. What is the atomicity of cesium chloride?
The atomicity of cesium chloride is 2.
374. Why is heptanol’s atomicity 24?
375. What is the molar mass of cesium chloride?
The molar mass of cesium chloride is 168.5 g/mol.
376. Why is calcium iodide’s molar mass 294 g/mol?
CaI₂ has 1 calcium and 2 iodines.
377. What is a molecule’s hybridization?
A molecule’s hybridization mixes atomic orbitals.
378. Why is methane’s carbon sp³ hybridized?
Carbon forms four equivalent bonds in methane.
379. What is the atomic mass of francium?
The atomic mass of francium is 223 amu.
380. Why is radium’s atomic mass 226 amu?
Radium’s atomic mass is based on its nucleus.
381. What is the molecular mass of francium chloride?
The molecular mass of francium chloride is 258.5 amu.
382. Why is octanol’s molecular mass 130 amu?
Octanol has 8 carbons, 18 hydrogens, 1 oxygen.
383. What is a mole of francium?
A mole of francium is 223 grams of Fr.
384. Why is a mole of radium 226 grams?
Radium’s molar mass is 226 g/mol.
385. What is the formula of francium chloride?
The formula of francium chloride is FrCl.
386. Why is KCl the formula of potassium chloride?
387. What is the atomicity of francium chloride?
The atomicity of francium chloride is 2.
388. Why is octanol’s atomicity 27?
389. What is the molar mass of francium chloride?
The molar mass of francium chloride is 258.5 g/mol.
390. Why is barium iodide’s molar mass 391 g/mol?
BaI₂ has 1 barium and 2 iodines.
391. What is a molecule’s bond angle?
A molecule’s bond angle is the angle between bonds.
392. Why is water’s bond angle 104.5°?
Water’s lone pairs repel bonds, reducing the angle.
393. What is the atomic mass of thallium?
The atomic mass of thallium is 204 amu.
394. Why is indium’s atomic mass 115 amu?
Indium’s atomic mass is based on its isotopes.
395. What is the molecular mass of thallium chloride?
The molecular mass of thallium chloride is 239.5 amu.
396. Why is nonanol’s molecular mass 144 amu?
Nonanol has 9 carbons, 20 hydrogens, 1 oxygen.
397. What is a mole of thallium?
A mole of thallium is 204 grams of Tl.
398. Why is a mole of indium 115 grams?
Indium’s molar mass is 115 g/mol.
399. What is the formula of thallium chloride?
The formula of thallium chloride is TlCl.
400. Why is CaCl₂ the formula of calcium chloride?
401. What is the atomicity of thallium chloride?
The atomicity of thallium chloride is 2.
402. Why is nonanol’s atomicity 30?
403. What is the molar mass of thallium chloride?
The molar mass of thallium chloride is 239.5 g/mol.
404. Why is strontium chloride’s molar mass 158.5 g/mol?
SrCl₂ has 1 strontium and 2 chlorines.
405. What is a molecule’s electron cloud?
A molecule’s electron cloud is its electron distribution.
406. Why is CO₂ linear?
CO₂’s double bonds align carbon and oxygens straight.
407. What is the atomic mass of gallium?
The atomic mass of gallium is 70 amu.
408. Why is germanium’s atomic mass 73 amu?
Germanium’s atomic mass is based on its isotopes.
409. What is the molecular mass of gallium chloride?
The molecular mass of gallium chloride is 105.5 amu.
410. Why is decanol’s molecular mass 158 amu?
Decanol has 10 carbons, 22 hydrogens, 1 oxygen.
411. What is a mole of gallium?
A mole of gallium is 70 grams of Ga.
412. Why is a mole of germanium 73 grams?
Germanium’s molar mass is 73 g/mol.
413. What is the formula of gallium chloride?
The formula of gallium chloride is GaCl₃.
414. Why is MgCl₂ the formula of magnesium chloride?
415. What is the atomicity of gallium chloride?
The atomicity of gallium chloride is 4.
416. Why is decanol’s atomicity 33?
417. What is the molar mass of gallium chloride?
The molar mass of gallium chloride is 176 g/mol.
418. Why is lithium bromide’s molar mass 87 g/mol?
LiBr has 1 lithium and 1 bromine.
419. What is a molecule’s symmetry?
A molecule’s symmetry is its balanced structure.
420. Why is CH₄ symmetrical?
Methane’s four hydrogens are evenly spaced.
421. What is the atomic mass of molybdenum?
The atomic mass of molybdenum is 96 amu.
422. Why is technetium’s atomic mass 98 amu?
Technetium’s atomic mass is based on its nucleus.
423. What is the molecular mass of molybdenum trioxide?
The molecular mass of molybdenum trioxide is 144 amu.
424. Why is ethanolamine’s molecular mass 61 amu?
Ethanolamine has 2 carbons, 7 hydrogens, 1 nitrogen, 1 oxygen.
425. What is a mole of molybdenum?
A mole of molybdenum is 96 grams of Mo.
426. Why is a mole of technetium 98 grams?
Technetium’s molar mass is 98 g/mol.
427. What is the formula of molybdenum trioxide?
The formula of molybdenum trioxide is MoO₃.
428. Why is NaF the formula of sodium fluoride?
NaF shows one sodium and one fluorine atom.
429. What is the atomicity of molybdenum trioxide?
The atomicity of molybdenum trioxide is 4.
430. Why is ethanolamine’s atomicity 12?
431. What is the molar mass of molybdenum trioxide?
The molar mass of molybdenum trioxide is 144 g/mol.
432. Why is potassium fluoride’s molar mass 58 g/mol?
KF has 1 potassium and 1 fluorine.
433. What is a molecule’s vibrational energy?
A molecule’s vibrational energy is due to bond movements.
434. Why do molecules absorb infrared light?
Molecules vibrate when absorbing infrared light.
435. What is the atomic mass of tungsten?
The atomic mass of tungsten is 184 amu.
436. Why is rhenium’s atomic mass 186 amu?
Rhenium’s atomic mass is based on its isotopes.
437. What is the molecular mass of tungsten trioxide?
The molecular mass of tungsten trioxide is 232 amu.
438. Why is glycine’s molecular mass 75 amu?
Glycine has 2 carbons, 5 hydrogens, 1 nitrogen, 2 oxygens.
439. What is a mole of tungsten?
A mole of tungsten is 184 grams of W.
440. Why is a mole of rhenium 186 grams?
Rhenium’s molar mass is 186 g/mol.
441. What is the formula of tungsten trioxide?
The formula of tungsten trioxide is WO₃.
442. Why is CaF₂ the formula of calcium fluoride?
CaF₂ shows one calcium and two fluorine atoms.
443. What is the atomicity of tungsten trioxide?
The atomicity of tungsten trioxide is 4.
444. Why is glycine’s atomicity 10?
445. What is the molar mass of tungsten trioxide?
The molar mass of tungsten trioxide is 232 g/mol.
446. Why is magnesium fluoride’s molar mass 62 g/mol?
MgF₂ has 1 magnesium and 2 fluorines.
447. What is a molecule’s rotational energy?
A molecule’s rotational energy is due to its spinning.
448. Why do molecules rotate?
Molecules rotate due to thermal energy.
449. What is the atomic mass of uranium?
The atomic mass of uranium is 238 amu.
450. Why is plutonium’s atomic mass 244 amu?
Plutonium’s atomic mass is based on its isotopes.
451. What is the molecular mass of uranium dioxide?
The molecular mass of uranium dioxide is 270 amu.
452. Why is alanine’s molecular mass 89 amu?
Alanine has 3 carbons, 7 hydrogens, 1 nitrogen, 2 oxygens.
453. What is a mole of uranium?
A mole of uranium is 238 grams of U.
454. Why is a mole of plutonium 244 grams?
Plutonium’s molar mass is 244 g/mol.
455. What is the formula of uranium dioxide?
The formula of uranium dioxide is UO₂.
456. Why is LiF the formula of lithium fluoride?
LiF shows one lithium and one fluorine atom.
457. What is the atomicity of uranium dioxide?
The atomicity of uranium dioxide is 3.
458. Why is alanine’s atomicity 13?
459. What is the molar mass of uranium dioxide?
The molar mass of uranium dioxide is 270 g/mol.
460. Why is barium fluoride’s molar mass 175 g/mol?
BaF₂ has 1 barium and 2 fluorines.
461. What is a molecule’s electronic energy?
A molecule’s electronic energy is due to electron transitions.
462. Why do molecules absorb UV light?
Molecules absorb UV light to excite electrons.
463. What is the atomic mass of thorium?
The atomic mass of thorium is 232 amu.
464. Why is protactinium’s atomic mass 231 amu?
Protactinium’s atomic mass is based on its nucleus.
465. What is the molecular mass of thorium dioxide?
The molecular mass of thorium dioxide is 264 amu.
466. Why is valine’s molecular mass 117 amu?
Valine has 5 carbons, 11 hydrogens, 1 nitrogen, 2 oxygens.
467. What is a mole of thorium?
A mole of thorium is 232 grams of Th.
468. Why is a mole of protactinium 231 grams?
Protactinium’s molar mass is 231 g/mol.
469. What is the formula of thorium dioxide?
The formula of thorium dioxide is ThO₂.
470. Why is SrF₂ the formula of strontium fluoride?
SrF₂ shows one strontium and two fluorine atoms.
471. What is the atomicity of thorium dioxide?
The atomicity of thorium dioxide is 3.
472. Why is valine’s atomicity 19?
473. What is the molar mass of thorium dioxide?
The molar mass of thorium dioxide is 264 g/mol.
474. Why is calcium bromide’s molar mass 200 g/mol?
CaBr₂ has 1 calcium and 2 bromines.
475. What is a molecule’s bond order?
A molecule’s bond order is the number of shared electron pairs.
476. Why is O₂’s bond order 2?
O₂ has a double bond between oxygen atoms.
477. What is the atomic mass of palladium?
The atomic mass of palladium is 106 amu.
478. Why is rhodium’s atomic mass 103 amu?
Rhodium’s atomic mass is based on its isotopes.
479. What is the molecular mass of palladium chloride?
The molecular mass of palladium chloride is 177 amu.
480. Why is leucine’s molecular mass 131 amu?
Leucine has 6 carbons, 13 hydrogens, 1 nitrogen, 2 oxygens.
481. What is a mole of palladium?
A mole of palladium is 106 grams of Pd.
482. Why is a mole of rhodium 103 grams?
Rhodium’s molar mass is 103 g/mol.
483. What is the formula of palladium chloride?
The formula of palladium chloride is PdCl₂.
484. Why is MgBr₂ the formula of magnesium bromide?
MgBr₂ shows one magnesium and two bromine atoms.
485. What is the atomicity of palladium chloride?
The atomicity of palladium chloride is 3.
486. Why is leucine’s atomicity 22?
487. What is the molar mass of palladium chloride?
The molar mass of palladium chloride is 177 g/mol.
488. Why is lithium iodide’s molar mass 134 g/mol?
LiI has 1 lithium and 1 iodine.
489. What is a molecule’s electronegativity?
A molecule’s electronegativity affects bond polarity.
490. Why is HF highly polar?
Fluorine has high electronegativity compared to hydrogen.
491. What is the atomic mass of ruthenium?
The atomic mass of ruthenium is 101 amu.
492. Why is osmium’s atomic mass 190 amu?
Osmium’s atomic mass is based on its isotopes.
493. What is the molecular mass of ruthenium chloride?
The molecular mass of ruthenium chloride is 207 amu.
494. Why is isoleucine’s molecular mass 131 amu?
Isoleucine has 6 carbons, 13 hydrogens, 1 nitrogen, 2 oxygens.
495. What is a mole of ruthenium?
A mole of ruthenium is 101 grams of Ru.
496. Why is a mole of osmium 190 grams?
Osmium’s molar mass is 190 g/mol.
497. What is the formula of ruthenium chloride?
The formula of ruthenium chloride is RuCl₃.
498. Why is NaCl the formula of sodium chloride?
499. What is the atomicity of ruthenium chloride?
The atomicity of ruthenium chloride is 4.
500. Why is isoleucine’s atomicity 22?
501. What is the molar mass of ruthenium chloride?
The molar mass of ruthenium chloride is 207 g/mol.
502. Why is potassium iodide’s molar mass 166 g/mol?
503. What is a molecule’s bond strength?
A molecule’s bond strength is its bond dissociation energy.
504. Why is N₂’s bond strong?
N₂ has a triple bond with high energy.
505. What is the atomic mass of iridium?
The atomic mass of iridium is 192 amu.
506. Why is platinum’s atomic mass 195 amu?
Platinum’s atomic mass is based on its isotopes.
507. What is the molecular mass of iridium chloride?
The molecular mass of iridium chloride is 298.5 amu.
508. Why is serine’s molecular mass 105 amu?
Serine has 3 carbons, 7 hydrogens, 1 nitrogen, 3 oxygens.
509. What is a mole of iridium?
A mole of iridium is 192 grams of Ir.
510. Why is a mole of platinum 195 grams?
Platinum’s molar mass is 195 g/mol.
511. What is the formula of iridium chloride?
The formula of iridium chloride is IrCl₃.
512. Why is CaI₂ the formula of calcium iodide?
CaI₂ shows one calcium and two iodine atoms.
513. What is the atomicity of iridium chloride?
The atomicity of iridium chloride is 4.
514. Why is serine’s atomicity 14?
515. What is the molar mass of iridium chloride?
The molar mass of iridium chloride is 298.5 g/mol.
516. Why is magnesium iodide’s molar mass 278 g/mol?
MgI₂ has 1 magnesium and 2 iodines.
517. What is a molecule’s lone pair?
A molecule’s lone pair
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