Question 1

Which of the following best describes the difference between an intensive and an extensive property? Choose the correct example for each.

Accepted Answer

Intensive properties do not depend on the amount of matter, such as density; extensive properties do, such as volume.

Question 2

A student mixes sand and salt in a beaker. Which classification best describes the resulting mixture?

Accepted Answer

Heterogeneous mixture

Question 3

Which of the following is a chemical property?

Accepted Answer

Flammability

Question 4

Which of the following statements about the structure of the atom is correct?

Accepted Answer

The nucleus contains protons and neutrons, and electrons occupy the surrounding space.

Question 5

Given the atomic symbol $$^{14}_{7}\mathrm{N}$$, how many neutrons does this atom have?

Accepted Answer

$$7$$

Question 6

Which of the following best explains why most alpha particles passed straight through the gold foil in Rutherford’s experiment?

Accepted Answer

The gold atoms are mostly empty space.

Question 7

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 8

A sample of natural uranium contains $$99.274\%$$ $$^{238}\mathrm{U}$$ and $$0.726\%$$ $$^{235}\mathrm{U}. $$What is the atomic weight of this sample? Use the formula $$	ext{Atomic weight} = (	ext{fraction}_1 	imes 	ext{mass}_1) + (	ext{fraction}_2 	imes 	ext{mass}_2).$$

Accepted Answer

$$237.98\ \mathrm{amu}$$

Question 9

Which of the following best describes a compound?

Accepted Answer

A substance formed from more than one element, with a fixed composition.

Question 10

Which property is both intensive and physical?

Accepted Answer

Density

Question 11

A pot of water is boiling on a stove. Which of the following best describes the energy transfer occurring?

Accepted Answer

Heat is being transferred from the stove to the water due to a temperature difference.

Question 12

Which of the following is NOT a pure substance?

Accepted Answer

Air

Question 13

Which of the following best describes the relationship between temperature and kinetic energy?

Accepted Answer

Temperature is a measure of the average kinetic energy of particles.

Question 14

Which of the following is a homogeneous mixture?

Accepted Answer

Salt dissolved in water

Question 15

Which of the following best explains why strontium poisoning is dangerous to humans?

Accepted Answer

Strontium replaces calcium in bones, disrupting normal bone function.

Question 16

Which of the following equations correctly represents the kinetic energy of a particle of mass $$m$$ moving at velocity $$v$$?

Accepted Answer

$$E_k = \frac{1}{2} m v^2$

Question 17

Which of the following is true about the periodic table?

Accepted Answer

Groups contain elements with similar chemical properties.

Question 18

Which of the following is an example of a physical change?

Accepted Answer

Dissolving sugar in water

Question 19

A sample contains only molecules of $$\mathrm{O}_2$$ and $$\mathrm{CO}_2. $$Which classification best describes this sample?

Accepted Answer

Mixture

Question 20

Which of the following best describes the main conclusion from Rutherford’s gold foil experiment?

Accepted Answer

Atoms have a small, dense, positively charged nucleus.

Matter, Atoms, and Their Properties: Foundations of General Chemistry

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