Winter Vacation Homework 2015-16
Worksheet 1
Class – VII
Chemistry
A) Write the chemical formulae of the following compounds ----------------i)
Calcium Sulphate –
ii)
Hydrogen Sulphide –
iii)
Potassium nitrate –
iv)
Magnesium Chloride –
v)
Sodium oxide –
B) Write the symbols for the following --------------------i)
Carbonate radical –
ii)
Hydroxide radical –
iii)
Phosphate radical –
iv)
Ammonium radical –
v)
Aluminium ion –
C) Make a 10-15 pages project on ‘Water and its applications’ in a project file.
D) Balance at least 15 chemical equations also.
****************************
Worksheet 2
Class – VII
Chemistry
A) Derive 20 Chemical formulae from your syllabus in a separate middle page of a file.
B) Complete the following table ---------------------Element
Sodium
Symbol
Atomic Mass
Protons Electrons Neutrons Valency Metals/
Number Number
Nonmetals
23
11
17
Phosphorous
31
C) Write the names of the following elements/ ions -------i)
Ca –
ii)
Mg+2 –
iii)
Ar –
iv)
H–
v)
Br-1 –
vi)
F–
vii)
SO4 -2 –
viii) Al –
ix)
CO3-2 –
x)
CD) Balance the following equations ---------------i)
N2 + H2  NH3
ii)
H2 + Cl2  HCl
iii)
H2 + O2  H2O
iv)
FeCl2 + Cl2  FeCl3
v)
CaCO3 + HCl  CaCl2 + H2O + CO2
**************************
18
15
Worksheet 3
Class – VII
Chemistry
A) Classify the following compounds into acid, bases and salts------Copper Nitrate, Zinc Oxide, Calcium Sulphate, Acetic Acid, Mg(OH)2 , H2SO4, CaO, CH3COOH,
Pb(NO3)2, HCOOH
B) Complete and Balance the following equations ----------------i)
HCl + NaOH 
ii)
Ca(HCO3) 
(heat)
iii)
CO2 + H2O 
iv)
HgO (heat) 
v)
Mg + O2 
C) Give two uses of the following -----------------i) Oxygen –
ii) Acids -
iii) Salts –
D) Collect different substances from your surroundings and paste in a scrap book and
mention whether it is an organic compound or an inorganic compound.
*********************