Question

is used by
ing
change, since only the physical properties of the
original state after the
en a fuel is burnt.
form of heat and
gy may either be
W new su
substances are changed.
ng a
change.
new substances during a
composition and the chemical properties of a substance are changed to form one or more
Interaction between two or more substances bring about a change. If the interaction increases the
All changes involve energy.
EXERCISES
heat.
Maltiple Choice Questions :
Select the correct option
occurs
a
When
1.
shape, size, colour,
change
a. energy is always absorbed
C. energy is either absorbed or
given out
b. energy is always given out
d. energy changes do not occur.
2.
Water can dissolve
a. solids only
b. solids and liquids only
d. liquids only
C. solids, liquids and gases
In a physical change
3.
a. the molecules of a substance do not change b. the molecules of the substances change
c. new substances are formed
C.
b. mostly irreversible
d. mostly reversible
brought in contact, it will result in
b. a chemical change only
4. Chemical changes are
a. always irreversible
always reversible
5. If two substances are
a. a physical change only
c. no changes
rent properties
ng
are
d. a chemical change if they are heated together, otherwise a physical change
nge
b. Baking a cake
d. Blooming of flowers
C.
6. Which of these is a reversible change?
a. Metal contracting
Ripening of fruits
7. Which of these is an irreversible change?
a. Melting of candle wax
c. Melting of ice
you change burnt
a. By cooling it
les
easons, melting of
8. How do
b. Burning of candle wax
d. Boiling of water
paper back into its original form?
b. By heating it
d. You cannot
c. By leaving it at room temperature
CHANGES AROUND US • B-25
uman beings are​

Answer 1

Answer:

Explanation:

melting of a candle is a physical change