Question

write the rule for making chemical formulas of compounds​

Answer 1

see the upper image that is your answer.

ok.

Answer 2

The rule for writing chemical formula is as follow:

Firstly, write the symbols with positive charge valency first. Secondly, write the valency of each atom on the top of its symbol. Thirdly, divide the valency number by their highest common factor ignore the positive or negative radicle.

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