Basic Concept
Which of the following is a physical change?
A. Burning wood
B. Rusting iron
C. Melting ice
D. Cooking food
C. Melting Ice
Which process involves both physical and chemical change?
A. Freezing
B. Burning candle
C. Cutting wood
D. Boiling water
B. Burning candle
Conversion of solid directly to gas is called:
A. Evaporation
B. Condensation
C. Sublimation
D. Fusion
C. Sublimation
Iron is painted to:
A. Improve color
B. Prevent rusting
C. Increase weight
D. Change shape
B. Prevent rusting
Breaking glass is irreversible because:
A. New substance forms
B. Shape cannot be restored
C. Chemical reaction occurs
D. Heat is produced
B. Shape cannot be restored
Dissolving sugar in water is:
A. Chemical change
B. Physical change
C. Both
D. Nuclear change
B. Physical Change
Which of the following is irreversible?
A. Melting ice
B. Stretching rubber
C. Burning paper
D. Dissolving sugar
C. Burning paper
Milk turning into curd is:
A. Physical
B. Chemical
C. Mechanical
D. Temporary
B. Chemical
LPG burning is a:
A. Physical change
B. Chemical change
C. Mechanical change
D. Reversible change
B. Chemical change
Boiling milk becomes chemical when:
A. It changes state
B. It cools
C. It spoils or burns
D. It evaporates
C. It spoils or burns
Which is NOT a physical change?
A. Sublimation
B. Evaporation
C. Combustion
D. Condensation
C. Combustion
Which is a physical change that can lead to chemical change?
A. Freezing water
B. Heating sugar
C. Breaking glass
D. Cutting paper
B. Heating sugar
Irreversible change means:
A. Can be reversed
B. Cannot be reversed
C. No change
D. Temporary change
B. Cannot be reversed
Digestion is a:
A. Physical process
B. Chemical process
C. Mechanical process
D. Temporary process
B. Chemical process
Which experiment best distinguishes chemical change?
A. Melting ice
B. Dissolving sugar
C. Burning magnesium
D. Breaking chalk
C. Burning magnesium
Which of the following forms a new substance?
A. Breaking chalk
B. Melting wax
C. Burning candle
D. Cutting paper
C. Burning Candle
Sublimation of camphor is:
A. Chemical
B. Physical
C. Both
D. Irreversible
B. Physical
Formation of new substance is called:
A. Physical change
B. Chemical change
C. Mechanical change
D. Periodic change
B. Chemical change
Baking cake involves:
A. Only physical change
B. Only chemical change
C. Both changes
D. No change
B. Only chemical change
Dissolving CO₂ in water is:
A. Physical only
B. Chemical only
C. Both physical and chemical
D. Nuclear
A. Physical only
Which change involves only change in state?
A. Cooking
B. Melting
C. Burning
D. Fermentation
B. Melting
Which statement is correct?
A. All irreversible changes are chemical
B. All physical changes are reversible
C. Some physical changes are irreversible
D. Chemical changes are always reversible
C. Some physical changes are irreversible
Rust is chemically known as:
A. Iron sulphide
B. Iron oxide
C. Iron carbonate
D. Iron chloride
B. Iron oxide
Rusting can be prevented by:
A. Heating
B. Cooling
Rusting can be prevented by:
A. Heating
B. Cooling
C. Coating
D. Breaking
D. Breaking
C. Coating
Classification of changes is difficult because:
A. No rules exist
B. Many changes involve both types
C. Physical changes don’t exist
D. Chemical changes don’t exist
B. Many changes involve both types