Question 1

Which of the following statements best describes an atom?

Accepted Answer

An atom is the smallest unit of a chemical element that retains its chemical properties.

Question 2

Which subatomic particle is responsible for the atomic number of an element?

Accepted Answer

Proton

Question 3

A neutral atom of oxygen has an atomic number of 8 and a mass number of 16. How many neutrons does it have?

Accepted Answer

$$8$$

Question 4

Which of the following best explains why neon (Ne) is chemically unreactive?

Accepted Answer

Its valence shell is full of electrons.

Question 5

How many valence electrons does a nitrogen atom (atomic number 7) have?

Accepted Answer

$$5$$

Question 6

Which of the following is true about isotopes?

Accepted Answer

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

Question 7

The isotope Carbon-14 has a half-life of 5,730 years. How many years will it take for a sample to decay to 1/4 of its original amount?

Accepted Answer

$$11,460$$ years

Question 8

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electrons between two atoms.

Question 9

What makes a covalent bond nonpolar?

Accepted Answer

The bonded atoms share electrons equally and have similar electronegativities.

Question 10

Which of the following is a property of hydrogen bonds?

Accepted Answer

They are weak individually but strong collectively, and are important in the structure of water and macromolecules.

Question 11

Which of the following best describes an anion?

Accepted Answer

An atom that has gained an electron and is negatively charged.

Question 12

Which of the following is NOT a use of radioactive isotopes?

Accepted Answer

Increasing the stability of atoms in living cells.

Question 13

Which of the following statements about ionic bonds is correct?

Accepted Answer

Ionic bonds are electrical attractions between oppositely charged ions.

Question 14

Which of the following best explains why water molecules are attracted to each other?

Accepted Answer

Water molecules are polar and form hydrogen bonds.

Question 15

A sodium atom (Na) loses one electron to become Na+. What type of ion is Na+?

Accepted Answer

Cation

Question 16

Which of the following is true about the octet rule?

Accepted Answer

Atoms are most stable when their outermost shell is full, usually with 8 electrons.

Question 17

Which of the following best describes the difference between intramolecular and intermolecular bonds?

Accepted Answer

Intramolecular bonds occur within a molecule, while intermolecular bonds occur between different molecules.

Question 18

Which of the following is a trace element required in small amounts for life?

Accepted Answer

Iron

Question 19

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are shared unequally due to differences in electronegativity.

Question 20

Which of the following neutral atoms would be most likely to lose an electron and become a cation of +1?

Accepted Answer

An atom with one electron in its outermost shell.

Atoms, Elements, and Chemical Bonding: Foundations of General Chemistry

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