CHEM120 Study Guide - Final Guide: Magic 2Ch, Electron Affinity, Endothermic Process
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Name: __________________________ Date: _____________
1. Which one of the following statements about atomic structure is false?
A) The electrons occupy a very large volume compared to the nucleus.
B) Almost all of the mass of the atom is concentrated in the nucleus.
C) The protons and neutrons in the nucleus are very tightly packed.
D) The number of protons and the number of neutrons are always the same in the
2. Which of the experiments listed below did not provide the information stated about the
nature of the atom?
A) The Rutherford experiment proved that the Thomson "plum pudding" model of the
atom was essentially correct.
B) The Rutherford experiment determined the charge on the nucleus.
C) Millikan's oil-drop experiment showed that the charge on any particle was a simple
multiple of the charge on the electron.
D) The cathode-ray tube proved that electrons have a negative charge.
3. The ion 16O2- has
A) 8 protons, 8 neutrons, 8 electrons
B) 8 protons, 8 neutrons, 10 electrons
C) 8 protons, 8 neutrons, 2 electrons
D) 8 protons, 8 neutrons, 10 electrons
E) 8 protons, 16 neutrons, 8 electrons
4. ______ form ions with a 2+ charge when they react with nonmetals.
A) Alkali metals
B) Alkaline earth metals
D) Noble gases
E) None of these choices
5. Which of the following formulas is not correct?
6. Which is the correct formula for gold(I) oxide?
7. Which of the following is not the correct chemical formula for the compound named?
8. The atomic mass of rhenium is 186.2. Given that 37.1% of natural rhenium is rhenium-
185, what is the other stable isotope?
9. The average mass of a boron atom is 10.81. If you were able to isolate a single boron
atom, what is the chance that you would randomly get an atom with mass 10.81?
C) about 11%
E) greater than 50%
HCl hydrogen chloride
Li2O lithium oxide
10. For which of the following compounds does 1.0 g represent 5.55 × 10-2 mol?
11. The mass of 0.82 mol of a diatomic molecule is 131.3 g. Identify the molecule.
12. NaHCO3 is the active ingredient in baking soda. How many grams of oxygen are in 0.32
g of NaHCO3?
A) 0.011 g
B) 1.0 g
C) 0.061 g
D) 0.0038 g
E) 0.18 g
13. Compound X2Y is 60% X by mass. Calculate the percent Y by mass of the compound
14. An oxybromate compound, NaBrOx, where x is a whole number, is analyzed and found
to contain 52.95% Br by mass. What is x?