Explanation:
Chemical formula of chloride of metal M is MCl₃
We know that Cl has valency 1.
nowzl, it's cleared that M had valency 3.
Bcz the after criss-cross it forms MCl₃.
Now,
Chemical formula of bicarbonate:
we know that bicarbonate has its valency/charge 1
So, after criss-cross the formula of metal bicarbonate is M(HCO₃)₃
Chemical formula of sulphide:
we know that sulphide has its valency/charge 2
So, after criss-cross the formula of metal metal is M₂S₃