Bonding
Covalent Bond
Introduction
Formed between atoms that share electrons is called a covalent bond
Molecules are formed when atoms combine
A molecule is a group of two or more atoms held together by covalent bonds.
Molecules of Elements
Sharing of two electrons forms a single covalent bond
A double bond is formed when two pairs of electrons are shared between two atoms.
Molecules of Compounds
Molecules made up of two or more different types of atoms linked together by covalent bonding are called molecular compounds or covalent compounds.
Physical properties
Low melting and boiling points
Very little heat energy is required to overcome the intermolecular forces.
Insoluble in water
Cannot conduct electricity
Do not have free-moving ions or electrons to conduct electricity
Ionic Bond
Introduction
May also known as electrovalent bond
Formed between Metals and Non-Metals
Attracted to both elements by electrostatic attraction
Compounds that contain ionic bonds are called ionic compounds
Examples?
Magnesium Fluoride
Sodium Chloride
Structure of Ionic Compounds
Form giant ionic structures
Arranged in giant lattice structure or crystal lattice
Physical properties
High melting and boiling points
Soluble in water
Cannot conduct electricity in solid form ; Can conduct electricity in liquid form
Cannot conduct : The ions are not free to move about
Can conduct : The ions are free to move about