In an endothermic reaction:
Energy is released
Energy is absorbed
Energy is neither released nor absorbed
Energy is not required
A seed growing into a tree is an example of:
Slow physical change
Fast periodic change
Slow natural change
Man made reversible change
Dissolving salt in water is a/an:
Endothermic change
Exothermic change
Both A and B
Chemical combination
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
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
The cells used in a wrist watch undergo:
Physical change
Periodic change
Chemical change
Cooking of rice is an example of:
Irreversible change
Endothermic reaction
Reversible change.
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:
Chemical decomposition
Oxidation
Melting of ice is an example of:
Exothermic reaction
