The making of a ring from gold is a ______ change and making a statue from wood is a _______ change
Irreversible, reversible
Reversible, irreversible
Irreversible, irreversible
Reversible, reversible
When you burn petrol,flames are produced. This is a/an
Endothermic reaction
Exothermic reaction
Physical change
Reversible reaction
Cooking of rice is an example of
Irreversible change
Both A and B
None
In a certain change, colour and the magnetic properties of a substance changed. What reaction might this be ?
Chemical combination
Photochemical reaction
Irreversible Reaction
The germination of a seed is:
A physical, reversible change in which energy is produced
A fast, chemical reaction in which energy is released
A slow, irreversible, desirable, chemical change
A fast, irreversible, undesirable chemical change
The cells used in a wrist watch undergo
Periodic change
Chemical change
None of these
Metals can be beaten into thin sheets. This property is called
Ductility
Elasticity
Volatility
Malleability
In a physical change
New substances are not formed
Reaction is reversible
Change is temporary
All of the above
Choose the electrochemical reaction from the following
Splitting water into hydrogen and oxygen by passing electricity
Producing electricity in a lechlanche cell
Both of the above
Choose the example of chemical combination reaction from the following
Coal burns in air
Water freezes on cooling
Oxygen and hydrogen react to give water
Ice melts on heating