Q: A toothpaste contains 12.0 g of calcium carbonate, 2.0 g of sorbitol, and 1.0 g of sodium lauryl sulfate. What is the percentage by mass of calcium carbonate in the toothpaste? Use the formula $$\text{\%} = \frac{\text{part}}{\text{whole}} \times 100\%.$$

$$\frac{12.0}{15.0} \times 100\% = 80\%$$

Q: A bullet contains $$11.6 g of $$lead, $$1.5 g of $$tin, and $$0.4 g of $$antimony. What is the percentage of tin in the bullet? Use $$\text{\%} = \frac{\text{part}}{\text{whole}} \times 100\%.$$

$$\frac{1.5}{13.5} \times 100\% = 11.1\%$$

Question 1

Which of the following best describes 'matter' as defined in chemistry?

Accepted Answer

Anything that has volume and takes up space

Question 2

A toothpaste contains 12.0 g of calcium carbonate, 2.0 g of sorbitol, and 1.0 g of sodium lauryl sulfate. What is the percentage by mass of calcium carbonate in the toothpaste? Use the formula $$	ext{\%} = \frac{	ext{part}}{	ext{whole}} 	imes 100\%.$$

Accepted Answer

$$\frac{12.0}{15.0} 	imes 100\% = 80\%$$

Question 3

Which of the following is NOT a step in the scientific method as described in the study materials?

Accepted Answer

Ignoring inconsistent results

Question 4

A student observes that a plant grows faster when placed near a window. She proposes that sunlight increases plant growth. What part of the scientific method is her proposal?

Accepted Answer

Hypothesis

Question 5

Which of the following statements best distinguishes a scientific law from a scientific theory?

Accepted Answer

A law is a summary of observed behavior, while a theory explains the reasons for that behavior.

Question 6

If $$(-3) + 8 is $$calculated, what is the result?

Accepted Answer

$$5$$

Question 7

Which of the following is an example of a chemical found in toothpaste that helps prevent cavities?

Accepted Answer

Sodium fluorophosphate

Question 8

Convert $$0.00086 to $$scientific notation.

Accepted Answer

$$8.6 	imes 10$$^{-4}$$

Question 9

A graph shows the volume of a balloon increasing as the temperature increases. What type of relationship is this?

Accepted Answer

Direct relationship

Question 10

Which of the following is a correct application of the rules for adding a positive and a negative number: $$7 + (-3)$$?

Accepted Answer

$$4$$

Question 11

A bullet contains $$11.6 g of $$lead, $$1.5 g of $$tin, and $$0.4 g of $$antimony. What is the percentage of tin in the bullet? Use $$	ext{\%} = \frac{	ext{part}}{	ext{whole}} 	imes 100\%.$$

Accepted Answer

$$\frac{1.5}{13.5} 	imes 100\% = 11.1\%$$

Question 12

Which of the following is an example of an observation in the scientific method?

Accepted Answer

Recording that you ran for 25 minutes on the treadmill

Question 13

Which of the following is NOT a recommended study strategy for learning chemistry?

Accepted Answer

Cramming all material the night before the exam

Question 14

What is the value of $$7 - (-3)$$?

Accepted Answer

$$10$$

Question 15

Which of the following best describes a hypothesis?

Accepted Answer

A possible explanation for an observation

Question 16

If $$2 	imes (-3) is $$calculated, what is the result?

Accepted Answer

$$-6$$

Question 17

Which of the following is a real-world example of a chemical law?

Accepted Answer

The law of gravity predicting that a dropped book will fall

Question 18

Express $$24,000 in $$scientific notation.

Accepted Answer

$$2.4 	imes 10$$^{4}$$

Question 19

A student is designing an experiment to test whether a new fertilizer increases plant growth. Which step should she perform immediately after forming her hypothesis?

Accepted Answer

Perform an experiment

Question 20

Which of the following is a correct statement about chemicals in everyday life?

Accepted Answer

Everything you see around you is made up of chemicals

Chapter 1: Chemistry in Our Lives – Foundations, Scientific Method, and Essential Skills

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