1.2 Bonding

Molecule

Two or more atoms held together by covalent bonds

Covalent bond

A shared pair of electrons

Dot and cross diagram

drawing to show the arrangement of the atoms or ions in a substance

Stick diagram

Use a line for a covalent bond

Elements that form covalent bonds

Non-metals

Strength of covalent bonds

Very strong

Lone pair electrons

Electrons that are paired up and are not part of a covalent bond

Diatomic molecule

A molecule made of two of atoms of the same substances

Common covalent substances

NH₄, O₂, H₂O

common diatomic molecules

H₂, N₂, O₂

Double covalent bond

bond in which two atoms share two pairs of electrons

Triple covalent bond

covalent bond formed by sharing three pairs of electrons

Formation of metal ions

Atoms lose outer electrons

Metals are

Elements that form positive ions

Formation of non-metal ions

Atoms gain electrons

Charge on non-metal ions

negative

Group ions charge/ valency

• Group 1- +1

• Group 2- +2

• Group 3- +3

• Group 4- ±4

• Group 5- -3

• Group 6- -2

• Group 7- -1

• Group 8- 0

Electron structure of ions

dot and cross diagram

Giant structure

A huge 3D network of atoms or ions

lattice

Regular arrangement of particle

Examples of Ionic compounds

NaCl, MgO

Ionic formula

the simplest whole number ratio of the ions in a giant ionic lattice

Giant ionic lattice

A huge 3D regular structure held together by the electrostatic forces of attraction between positive and negative ions

Electrostatic forces of attraction

The attractive force between oppositely charged particles.

Anion

A negatively charged ion

Cation

A positively charged ion

Elements in an ionic compound

Metals and a non-metal