Question 1

Which of the following best describes a chemical property?

Accepted Answer

Iron rusts when exposed to oxygen.

Question 2

A student observes that a piece of silver tarnishes and turns black after being left out in the air. What type of change is this?

Accepted Answer

Chemical change, because a new substance is formed.

Question 3

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Salt dissolved in water.

Question 4

Which of the following statements about elements is correct?

Accepted Answer

Elements are represented by chemical symbols, such as $$\mathrm{O}$$ for oxygen.

Question 5

A sample of gold has a mass of 89.4 g and a volume of 4.63 cm$$^3. $$What is the density of gold in g/cm$$^3$$?

Accepted Answer

$$19.3\ \mathrm{g/cm^3$}$$

Question 6

Which of the following processes represents a physical change?

Accepted Answer

Water freezes into ice.

Question 7

Convert a temperature of 25°C to Kelvin using the correct formula.

Accepted Answer

$$K = 25 + 273.15 = 298.15\ \mathrm{K}$$

Question 8

Which of the following is NOT a base SI unit?

Accepted Answer

Gram (g)

Question 9

A mass of 2.61 kg is how many grams?

Accepted Answer

2,610 g

Question 10

Which of the following best describes the difference between heat and temperature?

Accepted Answer

Heat is energy transferred from hotter to cooler objects; temperature is the average kinetic energy of molecules.

Question 11

Which of the following is a chemical change that occurs in the environment?

Accepted Answer

Iron in soil rusting after exposure to air and water.

Question 12

Which of the following is an example of potential energy?

Accepted Answer

A stretched rubber band.

Question 13

Which of the following is a correct scientific model?

Accepted Answer

A diagram showing the Bohr model of the atom.

Question 14

Which of the following is a compound?

Accepted Answer

NaCl

Question 15

A student writes 0.00017 in scientific notation. Which is correct?

Accepted Answer

$$1.7 	imes 10$$^{-4}$$

Question 16

Which of the following is a heterogeneous mixture?

Accepted Answer

Granite

Question 17

Which of the following is the correct formula for density?

Accepted Answer

$$d = m / V$$

Question 18

Which of the following is a physical property?

Accepted Answer

Water boils at 100°C.

Question 19

Which of the following is the correct conversion factor between calories and joules?

Accepted Answer

$$1\ \mathrm{cal} = 4.184\ \mathrm{J}$$

Question 20

Which of the following best describes a molecule?

Accepted Answer

A group of atoms bonded together as a unit.

Introduction to Chemistry: Matter, Properties, and Measurement

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