Page 240 - ICSE Chemistry 8

ASSESSMENT SHEET 2

A. Fill in the blanks.
1. ____________ is anything that has mass and occupies space.
2. ____________ have fi xed shape and volume.
3. The Kine c Theory of Ma er states that ma er consists of very small par cles that are constantly in
____________ and possess ______________.
4. The ____________ of the ma er and the ____________ occupied by the ma er may vary within a
system but the mass remains constant.
5. The total mass of the __________ is equal to the total mass of the _________ in a chemical reac on.
6. A ____________ refers to the transforma on of a substance from one form to another.
7. Changes that take place over a period of me are called ____________ changes.
8. ____________ changes occur due to human eff ort or ac vity.
9. An ____________ in the humidity in the air decreases the rate of evapora on.
10. A chemical change is ____________ and ____________.
11. A ____________ is a substance composed of two or more elements chemically combined in a
defi nite propor on by mass.
12. The process used to separate a mixture which has one of the components made up of iron is called
__________________.
13. The technique of __________________ is based on the principle of we ng of components of a
mixture.
14. _________________ is used to separate a mixture of miscible liquids.
15. _________________ is considered to be the simplest type of chromatography.
16. The metal plate connected to the posi ve terminal of the voltage source is called the ____________.
17. The number of electrons in an atom is equal to the number of protons in the atom which makes the
atom electrically ____________.
18. The arrangement of electrons in diff erent orbits or shells around the nucleus of an atom is called
________________.
19. Elements with valency two are called ____________ elements.
20. The chemical bond formed by sharing of electrons is called ____________.
21. The electrons present in the valence shell are called ______________.
22. A ____________ refers to a group of diff erent atoms present as a single unit having a posi ve or
nega ve charge.
23. A ____________ equa on has an equal number of atoms of one or more elements in the reactants
and products.
24. The __________________ states that ma er is neither created nor destroyed in a chemical reac on.
25. A ____________ alters the rate of a chemical reac on without itself undergoing any change.
26. When ammonium hydroxide and iron sulphide solu ons are mixed together, a brown-coloured
precipitate of ________________ is formed.
27. Enzyme _________ present in the living cells of yeast helps in the fermenta on of glucose in alcohol.
28. Zinc displaces ___________ from a solu on of copper(II) sulphate.
29. To neutralise the eff ect of an ant or a bee s ng, ________________ solu on or ________________
solu on is applied on the aff ected area.

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