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8th Maharashtra Board
IMPORTANT
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Give two examples of Element with valency 1.

Important Questions on Composition of Matter

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8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 4

Give two examples of element with valency 2.

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8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 5
Write the names and symbols of the constituent elements and identify their valencies from the molecular formulae given below.
KCl, HBr, MgBr2, K2O, NaH, CaCl2, CCl4, HI, H2S, Na2S, FeS, BaCl2
MEDIUM
8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 6

Chemical composition and name of some matter is given in the following table. Identify the main type of matter from its chemical composition.

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8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 7
Write scientific reason: Hydrogen is combustible, oxygen helps combustion, but water helps to extinguish fire.
MEDIUM
8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 7
Write scientific reason: Constituent substances of a colloid cannot be separated by ordinary filtration.
MEDIUM
8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 7
Write scientific reason: Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
MEDIUM
8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 7

Write scientific reason: A solid matter has the properties of definite shape and volume.

EASY
8th Maharashtra Board
IMPORTANT
General Science>Chapter 6 - Composition of Matter>Exercises>Q 8
Deduce the molecular formulae of the compound obtained from the following pairs of elements by the cross multiplication method. C (Valency 4) & Cl (Valency 1)