Representative Elements: Elements of the
third row which represent the characteristic properties of the elements of
the whole group to which they belong are called representative elements.
Ionisation Potential: The energy required
to remove an electron from an atom in the gaseous phase is called ionisation potential.
Electronegativity: The tendency of an
atom in a molecule to attract electrons towards itself from a covalent bond
is called electronegativity.
Electropositivity: The tendency of an
atom to donate electrons from its outermost shell is called electropositivity.
Oxidising Agents: The substance which
accepts electrons and makes another substance loose
electrons is called an oxidising agent.
Reducing Agents: The substance which loses electrons and
makes another substance accept electrons is called reducing agent.
Crystal Lattice: The orderly, geometrical, three-dimensional
pattern of atoms, ions or molecules present in a crystal is called crystal
Metallic Solids: Metallic solids consist of cations bound to free electrons by metallic bonds.
Covalent Solids: Substances in which the atoms in the entire
crystal lattice are held together by an extensive network of strong covalent
bonds are called network solids or covalent solids.
Molecular Solids: Substances in which small groups of
atoms-molecules are separated by distances larger than bond lengths are
called molecular solids.
Ionic Solids: Substances which consist of ions at the
lattice points are called ionic solids.
Metallic Bond: The force of attraction which binds metal cations to mobile electrons within its sphere of
influence in a metal is called metallic bond.
Body Centred Cubic Structure: A crystal unit cell
is said to be body-centred when there is a lattice
point (centre of a atom) at the centre of each cubic
Face Centred Cubic Structure: A crystal unit cell
is said to be face-centred when there is a lattice
point (centre of an atom) at the centre of each face of the unit cell.
Basic Oxides: Oxides of metals that react with water to
form an alkaline solution are called basic oxides. Basic oxides react with an
acid to give salt and water.
Acidic Oxides: Oxides of non-metals that react with water
to form acidic solution are called acidic oxides. Acidic oxides react with
bases to give salt and water.
Amphoteric Oxides: Oxides that react
with acids as well as bases to form salt and water are called amphoteric oxides.
Malleability: The tendency of a metal to undergo
flattening when hammered is called malleability.
Ductility: The tendency of a metal by which a wire can
be drawn from it is called ductility.