A seed growing into a tree is an example of:
Slow physical change
Fast periodic change
Slow natural change
Man made reversible change
Which of the following is a feature of physical change?
It is reversible
It is temporary
No new substance is formed
All of these
When nitrogen reacts with hydrogen under high temperature and pressure ammonia, which is also a gas is formed. This is an example of:
Chemical combination
Chemical decomposition
Physical change
Oxidation
Burning of a match stick is a/an:
Endothermic reaction
Exothermic reaction
Chemical change
Both B & C
Cloud seeding is a technique used to induce rain that was first used by USA in 1946. It has also been done in Karnataka and other places in India. What is it ?
An agricultural practice that depends on clouds
Introduction of particles in clouds to increase condensation
Making clouds and placed them in the sky
Trimming the clouds into seed like structures
Dissolving salt in water is a/an:
Endothermic change
Exothermic change
Both A and B
In an endothermic reaction:
Energy is released
Energy is absorbed
Energy is neither released nor absorbed
Energy is not required
The cells used in a wrist watch undergo:
Periodic change
None
On decreasing temperature, a liquid turns into solid. This is:
Condensation
Melting
Freezing
Sublimation
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
