Question 1

Which of the following best describes a hypothesis in the context of scientific investigation?

Accepted Answer

A testable explanation of a natural law.

Question 2

Which of the following is a physical property of matter?

Accepted Answer

Melting point

Question 3

A student mixes salt and sand together in a beaker. Which type of mixture have they created, and how could it be separated?

Accepted Answer

A heterogeneous mixture; by physical means such as filtration.

Question 4

Which of the following statements about atoms and molecules is correct?

Accepted Answer

A molecule is the smallest unit of a compound that retains its properties.

Question 5

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

Accepted Answer

Air

Question 6

A scientist measures the mass of a sample five times and gets values very close to each other, but all are far from the accepted value. This indicates the measurements are:

Accepted Answer

Precise but not accurate

Question 7

Which of the following best describes a systematic error in a scientific measurement?

Accepted Answer

An error inherent to the instrument that skews all measurements in the same direction.

Question 8

Which of the following numbers has four significant figures?

Accepted Answer

$$0.00120$$

Question 9

When adding $$10.45$$, $$10.5$$, and $$0.0012$$, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$20.95$$

Question 10

Which of the following best explains why trailing zeros in $$5000 g $$are not always considered significant?

Accepted Answer

Because there is no decimal point, so it is ambiguous whether the zeros are measured or just placeholders.

Question 11

A student multiplies $$5.000 	imes 25.0$$ and divides by $$4. $$What is the answer with the correct number of significant figures?

Accepted Answer

$$31.3$$

Question 12

Which of the following is an example of a chemical property?

Accepted Answer

Ability to undergo combustion

Question 13

Which of the following best describes a compound?

Accepted Answer

A substance containing a mixture of elements chemically combined in fixed proportions.

Question 14

Which of the following is NOT a correct statement about mixtures?

Accepted Answer

Mixtures cannot be separated by physical means.

Question 15

A sample of water is described as having a mass of $$10.500 g. $$How many significant figures does this measurement have?

Accepted Answer

Five

Question 16

Which of the following best describes the difference between precision and accuracy?

Accepted Answer

Precision is the degree of reproducibility; accuracy is how close a measurement is to the accepted value.

Question 17

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

Accepted Answer

Salad

Question 18

Which of the following statements about exact numbers is correct?

Accepted Answer

Exact numbers do not limit the number of significant figures in a calculation.

Question 19

A student measures the length of a metal rod as $$12.00 cm. $$Which of the following best describes the number of significant figures in this measurement?

Accepted Answer

Four

Question 20

Which of the following best describes the state of matter for a gas?

Accepted Answer

It has no fixed shape or volume and fills the entire container.

Introduction to Chemistry: Matter, Measurement, and Significant Figures

Guida di studio - Domande di pratica

Study guide - Flashcard