Answer:

Explanation:
Mass of one tablet = 20 mg
Mass of two tablets = 
Percent that is soluble in water = 40%
Mass of tablet that is soluble in water = 
So, mass of solute is 
Density of water = 1 kg/L
Volume of water = 1 L
So, mass of 1 L of water is 
PPM is given by

Hence, the concentration of iodine in the treated water
.
The electronic configuration of ‘N’ atom is 2, 5 and to have Octet in the valence shell it requires three more electrons.When two nitrogen atoms approach each other, each atom contributes 3 electrons for bonding.There are six electrons shared between two nitrogen atoms in the form of three pairs.Therefore, there is a triple bond between two nitrogen atoms in $N _{ 2 }$ molecules.
because it has ns1 electron configuration like the alkali metals