Advertisements
Advertisements
प्रश्न
What will you take into account while identifying the following?
A physical change in a substance.
Advertisements
उत्तर
Physical changes are those changes in which only the forms of substances get modified; the chemical natures and compositions of the substances involved are not altered.
Characteristics:
- No new substance is formed during a physical change.
- Most physical changes can be reversed easily.
- The chemical composition of a substance undergoing physical change remains the same.
संबंधित प्रश्न
Define physical change. Give two examples for the above changes.
Fill in the blank
Chemical change occurs as a result of __________ between two substances.
Write true or false
Melting of ice is a physical change.
Write true or false
Burning of sugar is a temporary change.
True or false
Is melting of ice a reversible change?
Which of the following are physical changes and which are chemical changes ?
Rusting of iron
Differentiate between a physical change and a chemical change with reference to – Nature of change is temporary and reversible or permanent and irreversible.
Is a change of state of matter – a physical or a chemical change. Give reasons.
Two drops of dilute sulphuric acid were added to 1 g of copper sulphate powder and then small amount of hot water was added to dissolve it (step I). On cooling, beautiful blue coloured crystals got separated (step II). Step I and Step II are:
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
