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5. Atoms,Molecules,Mixtures and Compound eLearn.Punjab

Chapter Review

1. Atoms are the building blocks of matter.
2. The simplest form of matter is called element.
3. Symbols are used to represent elements.
4. Elements are classified into: i. metals ii. non-metals
5. We use metals and non-metals according to their physical properties.
6. Elements combine chemically to form compounds.
7. When substances mix without showing chemical change, a mixture is formed.
8. Air is a mixture of gases.
9. Filtration, sublimation, distillation and paper chromatography are the methods of separating

components of mixtures.

Test Prepration

1. Write proper term/word against each statement.

i. Building blocks of matter _________________

ii. The matter consisting of only one kind of atoms _________________

iii. The process of separating components of a mixture having different boiling _________________

points

iv. The separation of coloured chemicals _________________

v. A solid changes into vapours without becoming a liquid _________________

3. Answer the following questions in detail.
i. Relate physical properties of metal elements with their uses.
ii. Define and explain compounds.
iii. What do you know about sublimation and distillation?
iv. Define paper chromatography and explain it with the help of an activity.
v. Write symbols of the following elements:

potassium nitrogen sodium gold mercury silver

4. Extend your thinking.
i. Why is water said to be a compound instead of an element?
ii. Explain why salt cannot be removed from a salt-water mixture by pouring the mixture through

a filter paper.

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