Class 7 chemistry physical and chemical change

Tick (✔) The correct choice amongest the following 1. Sublimation of iodine is a : (a) Chemical change (b) Physical change (c) Periodic change (d) Irreversible change 1 Mark(s) 2. When magnesium ribbon is burnt, heat and light are produced. It is an example of : (a) Chemical change (b) Physical and irreversible change (c) Chemical and exothermic change (d) Chemical and endothermic change 1 Mark(s) 3. Powdering of sugar is : (a) Chemical and irreversible change (b) Physical change (c) Reversible change (d) Irreversible change 1 Mark(s) 4. Making ice from water is an example of : (a) Man-made change (b) Chemical change (c) Sublimation (d) Undesirable change 1 Mark(s) 5. Melting of butter is not a : (a) Fast change (b) Desirable change (c) Reversible change (d) Permanent change 1 Mark(s)

Answer

Answers Tick (✔) The correct choice amongest the following 1. (b) Physical change 2. (c) Chemical and exothermic change 3. (b) Physical change 4. (a) Man-made change 5. (d) Permanent change

Write True False for each statement, Rewrite the false statements 1. In an exothermic reaction, heat is given out. 1 Mark(s) 2. In a chemical reaction no new substance is formed. 1 Mark(s) 3. Reaction of zinc pieces with hydrochloric acid is an exothermic reaction. 1 Mark(s) 4. Glowing of an electric bulb is a physical change. 1 Mark(s) 5. Breaking of a glass tumbler is a reversible change. 1 Mark(s) 6. Burning of wood is a chemical change. 1 Mark(s)

Answer

Write True False for each statement, Rewrite the false statements 1. True 2. False (New substance is formed) 3. False (An endothermic reaction) 4. True 5. False (Irreversible change) 6. True

Select the Odd and Out Giving reason 1. Burning of wood, rusting of iron, souring of milk, freezing of water. 1 Mark(s) 2. Freezing of water, magnetising an iron nail, breaking of chalk stick. 1 Mark(s) 3. Rusting, burning, combustion, melting. 1 Mark(s)

Answer

Select the Odd and Out Giving reason 1. freezing of water - others are chemical changes 2. burning of candle - others are physical changes 3. melting - others are chemical changes

Class 7 chemistry Matter around us

Tick (✔) The correct choice amongest the following

1. Which of the following is not a matter ? (a) Shadow (b) Chair (c) Toast (d) Juice

Answer

(a) Shadow

1 Mark(s)

2. What can be poured from one vessel to another ? (a) Solids (b) Fluids (c) Air (d) Water

Answer

(b) Fluids

1 Mark(s)

3. Maximum intermolecular spaces are present between : (a) Solids (b) Liquids (c) Gases (d) All of the above

Answer

(a) Solids

1 Mark(s)

4. Physical states of matter can be interchanged by : (a) Heating (b) Cooling (c) Heating or cooling (d) None of the above

Answer

(c) Heating and cooling

1 Mark(s)

5. Mixture of two phases : (a) Gas (b) Solid (c) Liquid (d) Vapour

Answer

Vapour

1 Mark(s)

Write True False for each statement, Rewrite the false statements

1. Solids have high densities, are rigid and hard.

Answer

True

1 Mark(s)

2. Gaseous state have least kinetic energy.

Answer

False

1 Mark(s)

3. Love, hate, shadow cannot be classified as matter.

Answer

True

1 Mark(s)

4. The process in which solid gets converted to liquid state is known as sublimation.

Answer

True

1 Mark(s)

5. Naphthalene and camphor are sublimable compounds.

Answer

False

1 Mark(s)

Select the Odd and Out Giving reason

1. Melting, freezing, evaporation, sublimation

Answer

Sublimation

1 Mark(s)

2. Napthalene, camphor, iodine, common salt

Answer

Common salt

1 Mark(s)

3. Water, juice, oil, ice-cream

Answer

Ice-cream

1 Mark(s)

Story Maker 1 from British Council