Question

What is the trick to learn the positive and negitive radicals

Answer 1

Explanation:

Valency:

Valency is the combining capacity of an element or radical.

For example, the valency of carbon is 4 because it combines with four atoms of hydrogen to yield methane (CH4).

Variable Valency

Sometimes, the same element may exhibit one valency in one compound and another valency in other compound. This property is called variable valency.