01.
|
i |
ii |
iii |
iv |
v |
|
C |
C |
B |
A |
A |
02.
i)
Combustion is the chemical reaction which involves the
burning of a substance in the presence of oxygen
ii)
Combustible materials are the materials that catch fire and burn
easily.
iii)
Flame is a zone of burning gas which produce heat and light.
iv)
Fire is the state or process of
combustion in which ignited material combines with oxygen and gives off light,
heat and flame.
v)
Firefighting is the
extinguishing of harmful fires.
03. Components required for the fire to burn are fuel, oxygen and heat.
04. (a)
i)
Rust is the reddish-brown coating on the metal surface.
ii)
Rusting is a chemical process that occurs in iron or steel.
(b) Necessary conditions for rust to
occur in iron or steel are moisture (water) and air (oxygen)
(c)
Methods of preventing rusting
ü Painting
ü Oiling
ü Galvanization
ü Tin plating
ü Use of silica gel
ü Use of plastic
