The nucleus of an atom contains... (choose all that apply)

• neutrons

• photons

• protons

• electrons

The atomic mass of an atom may be expressed as the sum of the masses of... (choose all that apply)

• electrons

• neutrons

• protons

The atomic number of an electrically neutral atom is equal to the number of...

• electrons

• protons

• neutrons

An element that has the electron configuration $1s^22s^22p^3$ has _______ electrons.

The electrons that occupy the outermost filled shell are called ______ electrons.

When all the electrons in an atom occupy the lowest possible energy states, the atom is said to be in its:

• ionized state

• ground state

• cold state

• regular state

Ideally speaking, bonds tend to form between two particles such that they are separated by a distance where _______ net force is exerted on them, and their overall energy is _________.

• a zero, maximized

• a non-zero, maximized

• a zero, minimized

• a zero, maximized

_________ bonds are the only primary bonds that are directionally dependent.

• ionic

• covalent

• metallic

Materials whose constituent particles are bound by which type of bond are generally expected to have the lowest melting temperatures?

• ionic

• covalent

• metallic

Why do ionic bonds form?

• So that the number of protons equals the number of electrons

• So that an atom can become unstable

• To fill the outermost energy level

• To share valence electrons with a neighbouring atom