Q: A sample of chlorine consists of two isotopes: $$^{35}\mathrm{Cl} (75.8$$% abundance, mass = 34.97 amu) and $$^{37}\mathrm{Cl} (24.2$$% abundance, mass = 36.97 amu). What is the average atomic mass of chlorine?

$$(0.758 \times 34.97) + (0.242 \times 36.97) = 35.45$$ amu

Q: A photon has a wavelength of $$4.00 \times 10$$^{-7}$$\ \mathrm{m}. $$What is its frequency? (Speed of light $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$7.50 \times 10$$^{14}$$\ \mathrm{Hz}$$

Question 1

Which of the following statements best explains the result of the Gold Foil Experiment conducted by Rutherford?

Accepted Answer

It demonstrated that atoms are mostly empty space with a small, dense, positively charged nucleus.

Question 2

Which of the following compounds is correctly named and matched with its formula?

Accepted Answer

Dinitrogen monoxide: $$\mathrm{N_2O}$$

Question 3

A sample of chlorine consists of two isotopes: $$^{35}\mathrm{Cl} (75.8$$% abundance, mass = 34.97 amu) and $$^{37}\mathrm{Cl} (24.2$$% abundance, mass = 36.97 amu). What is the average atomic mass of chlorine?

Accepted Answer

$$(0.758 	imes 34.97) + (0.242 	imes 36.97) = 35.45$$ amu

Question 4

Which of the following elements is a metalloid and what is a common property of metalloids?

Accepted Answer

Silicon; metalloids are semiconductors.

Question 5

Which of the following best describes what happens when an electron in an atom absorbs energy?

Accepted Answer

The electron moves to a higher energy level (excited state).

Question 6

What is the electron configuration for a neutral atom of phosphorus ($$Z=15$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^3$$

Question 7

Which of the following correctly predicts the ionic charge for an atom of magnesium when it forms an ion?

Accepted Answer

$$+2$$

Question 8

Which of the following is a property of ionic compounds?

Accepted Answer

They have high melting points and conduct electricity when dissolved in water.

Question 9

Given the name 'iron(III) chloride', what is the correct chemical formula?

Accepted Answer

$$\mathrm{$$FeCl_3$$}$$

Question 10

Which of the following best describes the difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

A polar covalent bond has unequal sharing of electrons, while a nonpolar covalent bond has equal sharing.

Question 11

Which of the following is the correct Lewis structure for carbon dioxide ($$\mathrm{CO_2$}$$)?

Accepted Answer

O=C=O, with each O atom having two lone pairs.

Question 12

Which of the following electromagnetic radiations has the highest energy?

Accepted Answer

Ultraviolet light

Question 13

A photon has a wavelength of $$4.00 	imes 10$$^{-7}$$\ \mathrm{m}. $$What is its frequency? (Speed of light $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$7.50 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 14

Which of the following is a correct statement about the octet rule and its exceptions?

Accepted Answer

Boron often forms compounds where it has only 6 valence electrons.

Question 15

Which of the following best describes the trend in atomic radius across a period from left to right?

Accepted Answer

Atomic radius decreases due to increasing nuclear charge.

Question 16

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH_4$)_2SO_4}$$

Question 17

Which of the following molecules is polar?

Accepted Answer

$$\mathrm{H_2O}$$

Question 18

Which of the following correctly ranks the intermolecular forces from weakest to strongest?

Accepted Answer

London dispersion \u003c dipole-dipole \u003c hydrogen bonding

Question 19

A transition metal forms a compound with the formula $$\mathrm{Fe_2O_3}. $$What is the charge on the iron ion in this compound?

Accepted Answer

$$+3$$

Question 20

Which of the following best describes a photon?

Accepted Answer

A quantum of electromagnetic energy.

Atoms, Elements, and Chemical Bonding: Study Guide for GOB Chemistry

Study Guide - Practice Questions

Study Guide - Flashcards