Page 127 - ICSE Chemistry 6

ASSESSMENT SHEET 2

A. Fill in the blanks.
1. _______________ was an early philosophical and spiritual fi eld of study that integrated chemistry
with metalwork.
2. _______________ discovered the concept of radioac ve half-life.
3. Aldrin, malathion and parathion are some major _______________ used to prevent crops and fruits
against pests.
4. Various _______________ are added to food products in order to increase their shelf life.
5. _______________ is an an bio c used to treat infec ons caused by bacteria.
6. The substances that do not have uniform composi on are called _______________ substances.
7. _______________ are the elements that possess the proper es of both metals and non-metals.
8. The atoms in a molecule are held by _______________.
9. _____________ are physical combina on of two or more elements or compounds in any propor on.

10. The technique of _______________ is daily used in our homes to separate tea leaves from tea using
a strainer.
11. _______________ is a force that tends to oppose mo on.

12. The volume of a liquid does not change with the forces of _______________.
13. _______________ forces are the intermolecular forces that exist between molecules of the same
substance.

14. The constant temperature at which a gas changes into a liquid is called the _______________.
15. Burning of paper causes a _______________ change.
16. _______________ is the purest form of water.
17. Water cycle helps to maintain the level of _______________ by restoring the lost water.
18. Mostly the solubility of solids and liquids in water increases with increase in _______________.
19. The process used to increase the rate of sedimenta on by addi on of chemicals is called
_______________.
20. _______________ is a period of abnormally low rainfall, leading to shortage of water.
21. Air exerts equal _______________ in all direc ons.
22. _______________ is present in water in dissolved form which is taken up by the aqua c animals for
respira on.
23. _______________ cons tutes about 78% of the air.
24. Substances which are burned to release energy are called _______________.

25. _______________ present in the earth’s stratosphere is responsible for protec ng us from harmful
ultraviolet rays.

B. State whether the given statements are true (T) or false (F).
1. Science is both a body of knowledge as well as a con nuous ongoing process.

2. There was a standardised scien fi c prac ce followed by the alchemists.
3. John Dalton gave the law of mul ple propor ons and the law of par al pressures.
4. Sorbic acid helps to prevent the growth of bacteria in food items.
5. Manufacturing of clothes involves the transforma on of fi bres into fabrics.

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