Chemistry of Life - Chapter 2

Subatomic particles

Protons
Neutrons
Electrons

Protons

Positively charged, Atomic Number

Neutrons

No charge/Neutral, Atomic mass - protons

Electrons

Negatively charged, Move around the nucleus in orbitals

Valence Shell

The outermost shell of an atom

Valence electrons

The electrons in the valance shell, they do the bonding

Valency

The amount of space left in the valence shell of the atom.

Hydrogen - 2

Covalent

When atoms share electrons

Electronegativity

An atom's attraction for the electrons in a covalent bond

The more electronegative an atom is, the stronger the attraction of electrons.

Polar covalent bond

Polar molecules share electrons UNEQUALLY, so one side is slightly negative and the other slightly positive (like water).

Nonpolar covalent bond

Nonpolar molecules share electrons EQUALLY, so there's no charge difference across the molecule (like oil).

Ionic bond

An ionic bond is formed when an atom transfers elections instead of sharing them

After taking one electron, the two atoms are now opposite and attract each other, the attraction holds them together

Hydrogen Bond

Bonds to Oxygen, Nitrogen, and Fluorine

Van der Waals interactions

Weak attractions between molecules that get very close

happen when electrons are not evenly distributed

Why a molecule's shape is important

The shape affects how it fits with other molecules

Chemical equilibrium

When the forward and reverse reactions happen at the same speed

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds