$$2.5\ \mathrm{kg} \times 2.2\ \mathrm{lbs/kg} = 5.5\ \mathrm{lbs}$$

$$\frac{0.25\ \mathrm{g}}{100\ \mathrm{g}} \times 100 = 0.25\%$$

Question 1

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

Accepted Answer

Air

Question 2

Which statement best describes a compound?

Accepted Answer

A substance containing two or more elements chemically combined in fixed ratios

Question 3

Which chemical symbol does NOT match its element name?

Accepted Answer

Pb for phosphorus

Question 4

A student measures the mass of a metal block as 45.6 g and its volume as 12.0 mL. What is the density of the block?

Accepted Answer

$$\frac{45.6\ \mathrm{g}}{12.0\ \mathrm{mL}} = 3.80\ \mathrm{g/mL}$$

Question 5

Which of the following is a physical change?

Accepted Answer

Melting ice

Question 6

Which of the following is NOT a correct statement about significant figures?

Accepted Answer

All zeros are always significant

Question 7

Convert 2.5 kg to pounds, given that 1 kg = 2.2 lbs.

Accepted Answer

$$2.5\ \mathrm{kg} 	imes 2.2\ \mathrm{lbs/kg} = 5.5\ \mathrm{lbs}$$

Question 8

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 9

A solution contains 15 g of NaCl dissolved in 100 mL of water. What type of matter is this?

Accepted Answer

Homogeneous mixture

Question 10

Which of the following best describes the law of conservation of energy?

Accepted Answer

Energy cannot be created or destroyed, only transformed

Question 11

Which of the following is the correct balanced chemical equation for the combustion of methane ($$CH_4) in $$oxygen?

Accepted Answer

$$CH_4 (g) + 2$$ $$O_2 (g$$) \rightarrow $$CO_2 (g) + 2 H_2O (g$$)$$

Question 12

Which of the following elements is a main-group element?

Accepted Answer

Sodium (Na)

Question 13

A student records the following measurements: 2.50 m, 2.51 m, 2.49 m, and 2.50 m. These measurements are:

Accepted Answer

Both precise and accurate

Question 14

Which of the following is the correct conversion factor to convert from milliliters to liters?

Accepted Answer

$$1\ \mathrm{L} = 1000\ \mathrm{mL}$$

Question 15

Which of the following statements about the periodic table is correct?

Accepted Answer

The periodic table organizes elements by increasing atomic number

Question 16

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

Accepted Answer

Chicken soup

Question 17

What is the specific gravity of a substance with a density of $$2.5\ \mathrm{g/mL}$$? (Density of water = $$1.0\ \mathrm{g/mL})$$

Accepted Answer

$$\frac{2.5}{1.0} = 2.5$$

Question 18

Which of the following is a correct statement about compounds?

Accepted Answer

Compounds are formed by elements in fixed ratios

Question 19

A sample contains 0.25 g of calcium in 100 g of a multivitamin tablet. What is the percent by mass of calcium in the tablet?

Accepted Answer

$$\frac{0.25\ \mathrm{g}}{100\ \mathrm{g}} 	imes 100 = 0.25\%$$

Question 20

Which of the following is a correct statement about dimensional analysis?

Accepted Answer

It is used to convert between units using conversion factors

Chapter 1: Introduction to Matter, Measurement, and the Periodic Table

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