- Basic Math and Science Atomic Structure and Bonding Questions and Answers Flashcards

Carbon-12 and Carbon-14 are isotopes. How do they differ?

Answer: Number of neutrons

Carbon-12 has 6 neutrons while Carbon-14 has 8 neutrons; both have 6 protons.

Which property of an atom is represented by its mass number?

Answer: Total number of protons and neutrons

The mass number equals the sum of protons and neutrons in the nucleus.

A polar covalent bond forms when two atoms share electrons:

Answer: Unequally, because one atom pulls electrons more strongly

In polar covalent bonds, the more electronegative atom attracts the shared electrons more strongly.

Which of the following best describes a cation?

Answer: An atom that has lost one or more electrons

A cation is a positively charged ion formed when an atom loses electrons.

In the Bohr model of the atom, electrons emit energy when they:

Answer: Move from a higher to a lower energy level

Electrons release a photon of energy when they fall from a higher to a lower energy level.

Which statement about noble gases is correct regarding chemical bonding?

Answer: They are largely unreactive due to a full valence shell

Noble gases have 8 valence electrons (or 2 for helium), giving them a stable configuration that makes them nearly inert.

What determines the number of valence electrons in a main-group element?

Answer: The group number

For main-group elements, the group number (1–18 system: groups 1, 2, and 13–18) directly indicates the number of valence electrons.