(a) Which two criteria did Mendeleev use to classify the elements in his periodic table?
(b) Which element of period '3' of the modern periodic table

(i) is the most reactive non-metal?

(ii) is the most reactive metal?

(iii) forms ion with -2 charge?

(iv) forms ion with +2 charge?

Question

Philoid · Accepted Answer

(a) Mendeleev used following two criteria to arrange elements in the periodic table:

1. The elements were arranged around to their increasing atomic masses.

2. He grouped elements having similar properties together.

(b) (i) The most reactive non-metal of period '3' of the modern periodic table is Chlorine (Cl).

(ii) The most reactive non-metal of period '3' of the modern periodic table is Sodium (Na).

(iii) The element in period 3 which forms ions with -2 charge is Sulphur (S).

(iv) The element in period 3 which forms ions with +2 charge is Magnesium (Mg).

(a) Which two criteria did Mendeleev use to classify the elements in his periodic table?(b) Which element of period '3' of the modern periodic table(i) is the most reactive non-metal?(ii) is the most reactive metal?(iii) forms ion with -2 charge?(iv) forms ion with +2 charge?