CBSE Class 9 Answered

Rules for writing the chemical formulae

Step 1 :  Write the symbol of a basic radical (element with a positive valency) on the left hand side and that of the acidic radical (element with a negative valency) on the right hand side.

Step 2 : Write the valency number/charge of each of the respective ions at the bottom of its symbol.

Step 3 : Interchange the valency number. Ignore the (+) and (-) sign.

Step 4 :  Write the interchanged number.

Step 5 :  Write the compound’s formula.

Step 6: Cross the reduced valencies. If 1 appears, ignore it.  And if a group of atoms receives a valency number more than 1, enclose it within brackets.