Which of the following is the easiest to change?
The colour of your hair
The shape of your face
The colour of your eyes
Both A & C
Burning of Magnesium ribbon is a ________ change.
Physical
Chemical
Reversible
Temporary
We keep food at low temperature in a refrigerator because it:
Saves money
Makes food more tastier
Kills bacteria present in the food
In fashionable to keep the food in the refrigerator
Identify the substance that evaporates at room temperature:
Water
Oil
Kerosene
Ammonium chloride
Melting of ice is an example of:
Exothermic reaction
Endothermic reaction
Chemical combination
Chemical decomposition
A chemical reaction in which energy is liberated is called:
Physical change
Photo chemical reaction
When a solid directly turns into gaseous state, it is called:
Sublimation
Condensation
Polymerisation
Melting
When nitrogen reacts with hydrogen under high temperature and pressure ammonia, which is also a gas is formed. This is an example of:
None of these
Burning of wood is a _________ change.
Cooking of rice is an example of:
Irreversible change
Both A and B