Revision worksheet-class 7
MATTER AND CHEMICAL FORMULAE

1 Write the chemical formulae of the following compounds
a. Copper sulphate
b. Sodium nitrate
c.Carbon-di-oxide
d. Ammonium Sulphate
e. Magnesium hydroxide.

2.Differenciate between atoms and molecules.
3.Define ores.Give any two examples
4.Can you separate the constituents of Fes( Iron sulphide) using a magnet? Give reason.
5.Give symbols of
Copper, Silver, Mercury, Gold,Iron Silicon, Aluminium, Chlorine
6. Write the atomicity of
Phosphorus, Nitrogen, Helium ,Ozone,Sulphur, Sodium
7Give reasons-
- Is copper an element
-water is acompound.
-Air is a mixture .
8.Name the elements present in Al2O3.Also write the valencies.
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