Hydrogen1p+, 1e_

Helium2p+, 2e_

electron

proton

neutron

The Atom

Sub Atomic Particles

Name Mass Charge Location

Proton 1 AMU + 1 Nucleus

Neutron 1 AMU N/A Nucleus

Electron N/A -1 Electron

Cloud

Carbon6p+, 6e_

Oxygen8p+, 8e_

Molecules• Chemical bonds hold together two or more

atoms of the same or different elements– Ex: Nitrogen gas: N2

• Chemical bond: a union between the electron clouds of two atoms

• Molecules of compounds-elements in proportions never vary.

SODIUMATOM11 p+

11 e-

electron transfer

CHLORINEATOM17 p+

17 e-

SODIUMION

11 p+

10 e-

CHLORINEION

17 p+

18 e-

Do not post photos to Internet1 mm

Molecular Hydrogen(H2)

Molecular Oxygen(O2)

Water (H2O)

Covalent bonding

Click to view animation.

Water molecule Ammonia molecule

Hydrogen bond

H H

O

Slight negative charge at this end

Slight positive charge at this end

No overall charge

Multiple H bonds holding two molecules together

Liquid water Ice

In-text FigurePage 20

Na+

Cl–

– –

––

––

–

––

– –

+ ++

+

+

+

+

+

+

+

+

++ +

+

+

+

+

cohesion

evaporation