Burning of paper is a______ change.

(a)

Physical

(b)

chemical

(c)

physical & chemical

(d)

neutral

The burning of matchstick is an example for chemical reaction based on______

(a)

Contact in physical states

(b)

electricity

(c)

light

(d)

catalyst

______ metal undergoes rusting.

(a)

tin

(b)

sodium

(c)

copper

(d)

iron

Rusting of iron is a _________ change.

(a)

physical

(b)

chemical

(c)

physical and chemical

(d)

neutral

Decomposition of limestone is an example for chemical reaction based on __________

(a)

contact

(b)

electricity

(c)

light

(d)

heat

Reactants → ______.

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Products

Photosynthesis is a chemical reaction that takes place in presence of _________.

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sunlight

Iron objects undergo rusting when exposed to ______ and ______.

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Water and oxygen

When quick lime comes in contact with When quick lime comes in contact with __________

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Slaked lime

The sides of the matchbox contains _________

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Red phosphorous

A chemical reaction is a temporary reaction.

(a) True

(b) False

Decomposition of lead nitrate is an example for a chemical reaction caused by light

(a) True

(b) False

Formation of slaked lime from quicklime is a endothermic reaction.

(a) True

(b) False

CFC is a pollutant.

(a) True

(b) False

Light energy may come out due to chemical reactions.

(a) True

(b) False

Rusting

(1)

Decomposition of limestone

Electrolysis

(2)

Pesticides

Thermolysis

(3)

Iron

Water pollution

(4)

Detergents

Land pollution

(5)

Brine