Question

Multiple Choice Questions
1. Valency of the elements in the halogen group is
a. One
b. two
c. three d. four
2. The most reactive element in the halogen group is
a. Astetine b. Iodine c. Chlorine d. Fluorine
3. The halogen which is liquid at room temperature is ...
a. Fluorine b. Astetine c. Bromine d. Iodine
4. The metallic character of elements
in a group from top to bottom.
a. increases b. decreases c. remains constant d. shows indefinite behaviour.
5. Valency of elements ...
in a period from left to right.
a. Increases
b. decreases
c. remains constant d. increases in the beginning and then decreases.
Exercise :​

Answer 1

Answer:

one

iodine

bromine

increases

increases

Answer 2

1 = a

2 = d

3 = c

4 = a

5 = b

reason 1 = Halogens belong to group `17 of periodic table and their general electronic configuration is ns2 np 5 .So, they have a tendency to accept one electron to get noble gas configuration

reason 2 = Flourine is the most reactive element in the halogen group.

This is because it has the smallest radius and most electronegative character.

reason 4 = Metallic character increases as you move down an element group in the periodic table. This is because electrons become easier to lose as the atomic radius increases, where there is less attraction between the nucleus and the valence electrons because of the increased distance between them

reason 5 = On moving from left to right in a period, the number of valence electrons decreases from 8 to 1