Atomic

Nucleus

The center of an atom that contains protons and neutrons and makes up the majority of the atom's mass.

Proton

A positively charged particle found in the nucleus of an atom.

Neutron

A neutral particle found in the nucleus, with a mass similar to that of a proton.

Electron

A negatively charged particle that orbits around the nucleus and is much smaller than protons and neutrons.

Atomic Symbol

A one or two-letter abbreviation for an element, with the first letter always capitalized.

Atomic Number

The number of protons in the nucleus of an atom, which determines the identity of the element.

Atomic Mass

The average or weighted mass of an atom, measured in atomic mass units (amu).

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Atoms with the same number of protons but different numbers of neutrons.

Molecule

Two or more atoms chemically combined, which can be of different or the same elements.

Compound

Two or more different elements chemically combined.

How do we calculate the number of neutrons in an atom?

Round the atomic mass to a whole number and subtract the atomic number.

What represents one atom of iron?

Fe represents one atom of iron.

What is the formula for the mass number?

Mass Number = Total number of Protons + Neutrons.