Time: 80
min
Instructions:
Answer all questions
1) For each of the
following items, choose the most correct answer from the given alternatives and
write its letter beside the number item.
i.
Which
state of matter with particles closely packed together?
A. Solid
B. Liquid
C. Gaseous
ii.
The
process through which a solid substance changes directly into gas without
passing liquid state is:
A. Sublimation
B. Deposition
C. Evaporation
iii.
Which
series of processes is correct for an ice to change into water vapour?
A. Melting, boiling
B. Melting,
deposition
C. Boiling,
condensation
iv.
An
element whose chemical symbol is the first two letters from its English name
is:
A. Magnesium
B. Calcium
C. Sodium
v.
Which
statement is not true about a physical change?
A. It is an
irreversible change
B. It is a
reversible change
C. It does not
affect the composition of the substance
vi.
Among
the following, which one is a chemical change?
A. Water freezes to
form an ice
B. A chalk grinded
into powder
C. An iron sheet
gets rust
vii.
Air
composes _______ % by volume of nitrogen.
A. 78
B. 21
C. 3
viii.
Which
method can be used to separate the mixture of water and floating solid
particles?
A. Decantation
B. Filtration
C. Fractional
distillation
ix.
Which
reason supports the statement “Water is a compound and not a mixture”?
A. Formation of
water involves chemical change
B. Formation of
water involves physical change
C. Components of
water may be seen separately
x.
The
condition in which the lungs are not getting enough oxygen causing difficult in
breathing is called:
A. Suffocation
B. Fainting
C. Shock
2) For each of the
following statements write TRUE if the statement is correct and FALSE if the
statement is incorrect.
i.
Changes
of states of matter is helpful in rainfall formation _________
ii.
Sour
of milk is the physical change of matter ______________
iii.
Air
is a homogeneous mixture that forms an alloy _______________
iv.
Mercury
is a liquid metal whose chemical symbol is Hg ________________
v.
Water
freezes to form water vapour __________
3) (a) Define the
following terms
i.
Matter
ii.
Boiling
point
iii.
Melting
point
iv.
Physical
change
v.
Chemical
change
(b) State any five (5) differences
between physical and chemical change.
4) (a) Changes of
states of matter is very important in our daily life. State any five (5)
importance of changes of states of matter.
(b) State whether each of the following
changes is either physical or chemical change.
i.
Drying
of a wet cloth
ii.
Melting
of an ice
iii.
Grinded
chalk
iv.
Evaporation
of water
v.
Decaying
of fish
5) (a) Air is a homogeneous
mixture of different gases in the atmosphere. Giving five (5) reasons, state
why air is mixture and not a compound.
(b) A metal X was left exposed to air
with moisture for two days. The metal was observed to have a reddish-brown colour
on its surface.
i.
What
is the name of element X?
ii.
Write
a chemical formula of element X
iii.
What
is the name of the colour observed on the metal surface?
iv.
Write
any two methods that can be used to remove the colour observed on a metal
surface.
