Chemistry IGCSE Comprehensive Exam Review, Exams of Science education
Ionic Bonding - ANSWERBetween a metal and a non-metal
1) soluble in water - polar water molecules are attracted to the giant 3D
crystal lattice and break it apart
2) conduct electricity when molten - when molten, the bonds have broken
and the electrons are free to move and carry charge
3) normally solids at room temperature - ions held in a fixed position by
strong bonds
4) higher melting and boiling points - strong ionic bonds in a 3D crystal lattice
that take much energy to break
Covalent Bonding - ANSWERBetween 2 non-metals
1) insoluble in water
2) brittle solids, liquids or gases at room temperature
3) don't conduct electricity when molten
4) lower melting and boiling points - molecules are held together by weak
intermolecular forces that are easy to break
Diatomic Gases: a nitrogen molecule has a triple bond, a carbon dioxide
molecule has two double bonds, an oxygen molecule has two double bonds.
, Cation - ANSWERPositive Ion
Anion - ANSWERNegative Ion
Metallic Bonding - ANSWERAn array of positive ions in a sea of delocalised
electrons. Most metals are hard and have high melting points. Good
conductors of heat. Malleable and ductile.
Solids - ANSWERParticles are closely packed in a regular structure. The only
movement the particles have is vibration.
Liquid - ANSWERParticles are still mainly touching but some gaps have
appeared. Liquids are usually less dense that the solid.
Gas - ANSWERParticles are much further apart and there are almost no forces
of attraction between them.
Changes of State - ANSWERSolid --> Liquid - Melting
Liquid --> Solid - Freezing
Liquid --> Gas - Boiling
Gas --> Liquid - Condensing
Solid --> Gas and Gas --> Solid - Sublimation
Diffusion - ANSWERThe spreading out of particles in a gas or a liquid. The
lighter the particles, the faster they diffuse. This is demonstrated by the
experiment with cotton wool soaked in ammonia solution at one end of a
tube and cotton wool soaked in HCl at the other end. The white cloud of
Ionic Bonding - ANSWERBetween a metal and a non-metal
1) soluble in water - polar water molecules are attracted to the giant 3D
crystal lattice and break it apart
2) conduct electricity when molten - when molten, the bonds have broken
and the electrons are free to move and carry charge
3) normally solids at room temperature - ions held in a fixed position by
strong bonds
4) higher melting and boiling points - strong ionic bonds in a 3D crystal lattice
that take much energy to break
Covalent Bonding - ANSWERBetween 2 non-metals
1) insoluble in water
2) brittle solids, liquids or gases at room temperature
3) don't conduct electricity when molten
4) lower melting and boiling points - molecules are held together by weak
intermolecular forces that are easy to break
Diatomic Gases: a nitrogen molecule has a triple bond, a carbon dioxide
molecule has two double bonds, an oxygen molecule has two double bonds.
, Cation - ANSWERPositive Ion
Anion - ANSWERNegative Ion
Metallic Bonding - ANSWERAn array of positive ions in a sea of delocalised
electrons. Most metals are hard and have high melting points. Good
conductors of heat. Malleable and ductile.
Solids - ANSWERParticles are closely packed in a regular structure. The only
movement the particles have is vibration.
Liquid - ANSWERParticles are still mainly touching but some gaps have
appeared. Liquids are usually less dense that the solid.
Gas - ANSWERParticles are much further apart and there are almost no forces
of attraction between them.
Changes of State - ANSWERSolid --> Liquid - Melting
Liquid --> Solid - Freezing
Liquid --> Gas - Boiling
Gas --> Liquid - Condensing
Solid --> Gas and Gas --> Solid - Sublimation
Diffusion - ANSWERThe spreading out of particles in a gas or a liquid. The
lighter the particles, the faster they diffuse. This is demonstrated by the
experiment with cotton wool soaked in ammonia solution at one end of a
tube and cotton wool soaked in HCl at the other end. The white cloud of
