Physical & chemical changes

1. PHYSICAL CHANGE
A change which alters some specific
physical property of the matter , like its
state, texture, magnetic or electrical
conditions or its colour without any
change in the composition of its
molecules, is called a physical change .
It also gets reversed if the cause
producing the change is removed.
Or changes in which no new substances
are formed.

2. Loss of water of crystallization(copper sulphate)

3. CHEMICAL CHANGE
A change which takes place in the state,
texture, colour, magnetic or electrical
properties along with change in the
composition of its molecules, is called a
chemical change . It does not get reversed
if the cause producing the change is
removed.
Or changes in which new substances are
formed.

4. Burning of magnesium ribbon
1 2
3 4

5. Differences between Physical and
Chemical changes
PHYSICAL CHANGE
No new substance
is formed.
CHEMICAL CHANGE
A new substance is formed.

6. PHYSICAL CHANGE
It is a temporary change
and can be easily reversed.
CHEMICAL CHANGE
It is a permanent change and
cannot be reversed

7. PHYSICAL CHANGE
Very little or no energy is
absorbed or given out
during a physical change
CHEMICAL CHANGE
A lot of energy is either given
out or absorbed during a
chemical change

8. PHYSICAL CHANGE
The mass of the substance does
not alter in a physical change
CHEMICAL CHANGE
The mass of a substance does get
altered in a chemical change

9. Q1) Give one example of a physical change.
Q2) Give one example of a chemical change.
Q3) Classify the following as physical and chemical changes:-
•Burning of candle wax ___________________________
•Melting of candle wax ___________________________
•Breaking a piece of chalk __________________________
•Germination of seed ______________________________
•Formation of curds from milk _______________________
•Condensation of steam ____________________________
Q4) A person eats a chocolate and then digests it . In doing so
there takes place a physical and a chemical change .identify
the changes and give a reason for your answer.