foundation chemistry

Atom

The building block of matter made of protons, neutrons, and electrons

Proton

A positively charged particle found in the nucleus of an atom

Electron

A negatively charged particle found in shells around the nucleus

Valence electron

Electrons in the outermost shell

Ion

An atom or molecule with an electrical charge

Neutral

No charge

Ionic Compound

A neutral compound consisting of positive and negative ions held together by ionic bonds

Ionic Bond

Electrostatic attraction between positive and negative ions

Group

A vertical column of elements

What do elements in the same group have in common?

They have the same number of outer electrons, called valence electrons

Period

Horizontal row on the periodic table

What do elements in the same period have in common?

As you move across a period from left to right, each element adds one proton and one electron, changing properties from metal to non-metal