Enfant India
International School
Semester I 2020-21
Std- VII Subject- Chemistry M:M-40
Section
I ( 20 marks )
Q1-Write
true or false against each statement: 5m
i.
Digestion of food is a physical change.
ii.
A compound is a pure substance.
iii.
Carbon dioxide is an element.
iv.
The symbol of Carbon is C.
v.
Nucleus is negatively charged.
Q2-Fill in the blanks with the suitable words- 5m
i-
The substance taking part in chemical
reaction is called……………
ii-
Water breaks down into its constituents
hydrogen and…………….
iii-
A chloride ion has one unit…………… charge.
iv-
Sugar solution is a………..…. mixture.
v-
Photosynthesis is a………..…. change.
Q3-Choose
the correct option- 5m
i-
Elements present in carbonate ion are-
a. Carbon
and oxygen b. Carbon and
hydrogen
ii-
The number of valence electrons in magnesium
atom is-
a. 2 b. 1
iii-
The molecular formula of water is-
a. H2O b. N2O
iv-
The symbol of sodium is-
a. N b. Na
v-
An example of chemical change is-
a. Cutting
of wood b. Burning
of wood
Q4- Give
one word for the following- 5m
i.
The process in which solid directly changes
into a gas.___________
ii.
Unreactive gases which are present in traces
in air._____________
iii.
Small dense and positively charged central
core of an atom.______
iv.
The substance formed in the chemical reaction._____________
v.
These are written on the left-hand side of
the reaction.__________
Section
II ( 20 marks )
Q5- Define
any three of the following
terms-
2X3=
6m
i.
Atomic number
ii.
Radical
iii.
Electronic configuration
iv.
Atom
v.
Mass number
Q6- Differentiate
between the following- 2X2=
4m
i.
Reactants and products
ii.
Compound and mixtures
Q7- Give
reasons for the following-
2X2= 4m
i-
Why do we need to classify elements.
ii-
Why elements are called pure substances.
Q8- Answer
the following questions- 2X3= 6m
i-
What is a chemical reaction?
ii-
Give the symbols of the following-
A. Sulphur
B. Phosphorus
C. Calcium
D. Chlorine
iii-
Give the valencies of the following radicals-
A. Carbonate
B. Sulphate
