Question 1

Which of the following best describes a physical change?

Accepted Answer

Dissolving table salt in water

Question 2

Which of the following is a homogeneous mixture?

Accepted Answer

Air

Question 3

What is the correct scientific notation for the number 0.00056?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 4

Which of the following elements is a nonmetal?

Accepted Answer

Chlorine (Cl)

Question 5

Which statement about subatomic particles is correct?

Accepted Answer

Neutrons have no charge and are found in the nucleus.

Question 6

Which of the following is the correct balanced equation for the reaction of hydrogen gas with oxygen gas to form water?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O$$

Question 7

A radioactive isotope has a half-life of 4 hours. If you start with 80 grams, how much will remain after 12 hours?

Accepted Answer

10 grams

Question 8

Which of the following ions has the same electron configuration as neon ($$Ne$$)?

Accepted Answer

$$Na^+$$

Question 9

Which of the following molecules is polar?

Accepted Answer

$$H_2O$$

Question 10

What is the percent by mass of sodium in sodium chloride ($$NaCl$$)? (Atomic masses: $$Na = 23$$, $$Cl = 35.5)$$

Accepted Answer

$$39.3\%$$

Question 11

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve 8 electrons in their outermost shell.

Question 12

Which of the following is the correct Lewis structure for $$NH_3 ($$ammonia)?

Accepted Answer

N with three single bonds to H and one lone pair on N

Question 13

Which of the following best describes a covalent compound?

Accepted Answer

A compound formed by the sharing of electrons between nonmetals

Question 14

Which of the following is the correct conversion of 98°F to Kelvin? (Use $$K = \frac{5}{9}(°F - 32) + 273.15)$$

Accepted Answer

$$309.15\ K$$

Question 15

Which of the following best describes the VSEPR shape of $$CO_2$$?

Accepted Answer

Linear

Question 16

Which of the following is a correct statement about metals and nonmetals in the periodic table?

Accepted Answer

Metals are generally found on the left side and nonmetals on the right side of the periodic table.

Question 17

Which of the following nuclear decay reactions represents beta decay?

Accepted Answer

$$^{14}_{6}C \$$rightarrow ^{14}$$_{7}N $$+ ^{0}$$_{-1}e$$

Question 18

Which of the following best describes a dipole moment arrow?

Accepted Answer

It points from the positive to the negative end of a polar bond.

Question 19

Which of the following is the correct formula for an ionic compound formed between magnesium and chlorine?

Accepted Answer

$$MgCl_2$$

Question 20

Which of the following is NOT a property of matter?

Accepted Answer

Radioactivity

GOB Chemistry Exam 1 Study Guide: Chapters 1–3

Study Guide - Practice Questions