Question

Elements X and Y belong to Group 1 and Group17 respectively of the periodic table.

a) Predict the valency of X and Y. b) Identify the element which forms cation and the element which forms anion. c) Give the molecular formula of the oxide formed by X

d) If X and Y form oxides, which is the most acidic oxide?

e) How will the non metallic character vary on moving from X to Y?

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Answer 1

Answer:

a) valency x = 1+, y = 1-

b) x forms cation and y forms anion

c) XO2

d) Y's will be more acidic

e) X mettalic character decreasing to Y

Answer 2

Answer:

a) The valence number of electrons in X is 1 and in Y is 2.

b) The valency of the element is determined by the number of electrons in the outermost shell . Thus, the valency of element X is 1 and Y is 2.

c) Element X is more metallic than Y.

d) The size of element X is more than Y.

e) The formulae of oxide of element X is X

2

O and Y is YO

The formulae of chlorides of element X is XCl and Y is YCl

2