Q14 of 30 Page 196

For the main groups of periodic table given as follows:


(a) Which element is the most metallic?


(b) Which atom is the largest?

(a) We know that metallic character decreases from left to right in a period and metallic character increases down a group. So element C is the most metallic.

(b) We know that the size of atom decreases from left to right in a period and size of atom increases down a group. So atom C is the largest.


More from this chapter

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12

Which one has the smaller size?

K (19) or Na (1); B (5) or C (6)

 13

Calcium is an element with atomic number 20.

(i) Is it a metal or non-metal?


(ii) Is it more reactive than Mg or less?


(iii) What will be its valency?


(iv) What will be the formula of its Chloride?


(v) Will it be larger than K or smaller?

 15


(a) Which is the most reactive metal?


(b) Which is the most reactive non-metal?


(c) Name the family of L, Q, R, T


(d) Name one element from each of groups 2, 13 and 15.

16

This question refers to the elements of the periodic table with atomic numbers 3 to 18.

(a) (i) Which of them are noble gases?


(ii) Which of them are halogens?


(iii) Which of them are akali metals?


(iv) Which are the elements with valency 4?


(b) An element with atomic no. 3 combines with another element with atomic number 17; what would be the formula of the compound?


(c) What is the electronic configuration of an element with atomic number 10?