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

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

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

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

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1 Mark(s)

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

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1 Mark(s)

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

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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

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1 Mark(s)

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

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1 Mark(s)

Write True False for each statement, Rewrite the false statements

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

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1 Mark(s)

2. Gaseous state have least kinetic energy.

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1 Mark(s)

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

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1 Mark(s)

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

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1 Mark(s)

5. Naphthalene and camphor are sublimable compounds.

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1 Mark(s)

Select the Odd and Out Giving reason

1. Melting, freezing, evaporation, sublimation

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1 Mark(s)

2. Napthalene, camphor, iodine, common salt

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1 Mark(s)

3. Water, juice, oil, ice-cream

Answer

1 Mark(s)