Question 1

Which of the following best describes a pure substance?

Accepted Answer

A material with a uniform and definite composition, either an element or a compound.

Question 2

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

Accepted Answer

A salad with lettuce, tomatoes, and cucumbers

Question 3

Which state of matter has a definite shape and definite volume?

Accepted Answer

Solid

Question 4

When water is boiled, what happens to the molecules?

Accepted Answer

The molecules separate from each other, with the atoms still sticking together in molecules.

Question 5

Which phase of matter will molecules be moving the most?

Accepted Answer

Gas

Question 6

During a physical change, such as melting ice, what changes and what stays the same?

Accepted Answer

Physical state changes, but chemical composition stays the same.

Question 7

Which of the following is a chemical change?

Accepted Answer

Charcoal is covered in a layer of ash after burning.

Question 8

Convert 42.0 °F to Celsius using the correct formula.

Accepted Answer

$$C = \frac{5}{9}(F - 32)$$

Question 9

A refrigerator maintains an inside temperature of 42.0 °F. What is this temperature in Kelvin?

Accepted Answer

$$K = \frac{5}{9}(42.0 - 32) + 273.15$$

Question 10

Your body temperature is 38.2 °C. What is your temperature in Fahrenheit?

Accepted Answer

$$F = \frac{9}{5}C + 32$$

Question 11

Which of the following is NOT a physical change?

Accepted Answer

Meat browning on a grill

Question 12

Which temperature scale is based on absolute zero?

Accepted Answer

Kelvin

Question 13

What is the freezing point of water in Kelvin?

Accepted Answer

$$273.15\ K$$

Question 14

Which of the following is a homogeneous mixture?

Accepted Answer

Air

Question 15

Which of the following statements about gases is correct?

Accepted Answer

Gases have no definite shape or volume.

Question 16

Which formula would you use to convert Celsius to Kelvin?

Accepted Answer

$$K = C + 273.15$$

Question 17

Which of the following is an example of a compound?

Accepted Answer

Table salt ($$NaCl)$$

Question 18

Which of the following changes involves a change in chemical composition?

Accepted Answer

Charcoal turning to ash

Question 19

Which of the following is true about molecular movement in solids?

Accepted Answer

Molecules vibrate in fixed positions.

Question 20

A student mixes sand and salt together. What type of mixture is this?

Accepted Answer

Heterogeneous mixture

Chap 3. Classification of Matter, States of Matter, Physical and Chemical Changes, and Temperature Scales

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