Question 1

Which of the following statements best explains why carbon dioxide ($$CO_2) is a $$nonpolar molecule, even though it contains polar bonds?

Accepted Answer

The molecule is linear, so the dipoles cancel each other out.

Question 2

Water ($$H_2O) is a $$polar molecule. Which of the following best describes the reason for its polarity?

Accepted Answer

It has a bent molecular geometry and polar O-H bonds.

Question 3

Which scientist is credited with discovering the law of conservation of mass?

Accepted Answer

Antoine Lavoisier

Question 4

According to Dalton's atomic theory, which of the following statements is correct?

Accepted Answer

Atoms of different elements are different from each other.

Question 5

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically bonded together.

Question 6

Why can't linear molecules like $$CO_2 be $$polar?

Accepted Answer

The dipole moments of the bonds cancel each other out due to the linear geometry.

Question 7

Which of the following is NOT a postulate of Dalton's atomic theory?

Accepted Answer

Atoms can be divided into protons, neutrons, and electrons.

Question 8

A student mixes two colorless solutions and observes the formation of a white solid. Which type of change has occurred?

Accepted Answer

A chemical change, because a new substance (precipitate) is formed.

Question 9

Which of the following best describes a molecule?

Accepted Answer

A group of atoms chemically bonded together.

Question 10

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

Accepted Answer

Ice melting to form liquid water.

Question 11

Which of the following best explains why $$H_2O$$ has a bent molecular shape?

Accepted Answer

The two lone pairs on oxygen repel the hydrogen atoms, creating a bent geometry.

Question 12

Which of the following is a correct statement about elements and compounds?

Accepted Answer

Elements are made of only one type of atom, while compounds are made of two or more elements chemically combined.

Question 13

Which of the following is a correct example of the law of conservation of mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 14

Which of the following best describes a chemical property?

Accepted Answer

The ability of a substance to react with oxygen.

Question 15

Which of the following is a correct statement about protons, neutrons, and electrons?

Accepted Answer

Protons and neutrons are found in the nucleus, while electrons are found outside the nucleus.

Question 16

Which of the following is an example of a mixture?

Accepted Answer

Air, because it contains several gases physically combined.

Question 17

Which of the following best describes the difference between a physical and a chemical change?

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

Question 18

Which of the following is a correct statement about molecules and compounds?

Accepted Answer

All compounds are molecules, but not all molecules are compounds.

Question 19

Which of the following best describes the structure of an atom?

Accepted Answer

A nucleus containing protons and neutrons, with electrons in orbitals around the nucleus.

Question 20

Which of the following is a correct example of a chemical change?

Accepted Answer

Burning wood to produce ash and gases.

Fundamental Concepts in General Chemistry: Atoms, Molecules, and Chemical Bonding

Study Guide - Practice Questions