Bonding and Structure (atoms, elements, molecules)

An element is one type of atom

Two or more things which are not chemically bound

Two or more things which are chemically bound

Proton ~ +1 Neutron ~ 0 Electron ~ -1

Proton ~ 1 Neutron ~ 1 Electron ~ 1/2000

Cations - positive ions Anions-negative ions

Cations - metals lose an electron and turn into a positive ion Anions - non-metals gain an electron and turn into negative ions

The strong electrostatic force of attraction between positive ions & negative ions/ positively charged

• High melting & boiling points because of strong electrostatic force of attraction between the oppositely charged ions • good electrical conductivity when aqueous or molten because the ions are separated and have their own charge • generally soluble in water.

Giant lattice structure, which is the regular arrangement of alternating positive & negative ions

molecules that contain only two atoms bonded to one another Group 7 & oxygen, nitrogen, hydrogen

A shared pair of electrons

When pair of electrons is shared between two atoms, to make a full outer shell

• Low melting & boiling points due to week intermolecular forces • poor electrical conductivity as they do not have charge

The inter molecular forces are weak which makes it slide easily & there is one free electron

Each carbon atom is bonded to each other & the intermolecular forces are very strong

The electrostatic force of attraction between positive nuclei and a sea of negative delocalised electrons in a giant metallic lattice structure

• Good electrical conductivity because there are free electrons to carry charge • malleable, (can be reshaped using a hammer) because their layers slide • ductile can be stretched into a wire