Which of the following is not a reversible change?
Heating of water to steam
Cooking of egg to scrambled eggs
Heating of wax to molten wax
Cooling a cake
When liquids are heated, they turn into gases. The yellow egg yolk present inside the egg is a liquid but when it is heated, it changes into an omelet which is solid, why?
Sometimes, liquids turn into solids
Omelet does not follow the above rule
Strictly speaking, the rule does not apply to complex mixtures and egg yolk is a complex mixture
None
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
Which of the following is a feature of physical change?
It is reversible
It is temporary
No new substance is formed
All of these
A chemical reaction in which energy is liberated is called:
Exothermic reaction
Physical change
Endothermic reaction
Photo chemical reaction
Identify the substance that evaporates at room temperature:
Water
Oil
Kerosene
Ammonium chloride
Melting of ice is an example of:
Chemical combination
Chemical decomposition
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
When a solid directly turns into gaseous state, it is called:
Sublimation
Condensation
Polymerisation
Melting
In an endothermic reaction:
Energy is released
Energy is absorbed
Energy is neither released nor absorbed
Energy is not required
