ICSE Class 7 Answered

Chemical formula of Potassium Chlorate is KClO₃ .

Potassium Chlorate is madeup of K⁺ and ClO^-₃ ions. These ions have +1 and -1 charges.

Radical

    Radical is an atom or a group of atoms of same or different elements which behaves like a single atom with a positive or a negative charge on it. 

    Radicals have their own combining power based on which they form chemical formulae. 

 Example: 

    NH₄⁺, Na⁺, NO₃⁻, SO₄²⁻ 

Valency of an atom is equal to the number of electrons in the outer shell.

If the number of electrons in the outermost shell is four or less than four then it is the valency of that atom. Otherwise, the valency is eight minus the number of electrons in the outermost shell.

If you know the number of electrons in the outer shell then you can calculate the valency.