Matter: Atoms

The parts of an atom are _____.

• protons, neutrons, and electrons

• elements, compounds, and mixtures

• periods, groups, and columns

____ are found in the nucleus of the atom.

• protons and electrons

• protons and neutrons

• electrons and neutrons

____ orbit the nucleus.

• protons

• neutrons

• electrons

The atomic number tells us the number of ___ in the atom.

• electrons

• neutrons

• protons

If you know the number of protons in an atom, you automatically know the number of ___.

• electrons

• neutrons

The mass number of the atom tells you the number of ____.

• protons and electrons

• protons and neutrons

• electrons and neutrons

You can figure out the number of neutrons by ____ the protons from the mass.

• adding

• subtracting

• multiplying

• dividing

Electrons orbit the nucleus in ___.

• shells

• rings

• clouds

• all of these

Valence electrons are found in the ___ ring.

• innermost

• outermost

• middle

Valence electrons determine the ____ of the atom.

• size

• shape

• reactivity

• age