Question

Write the molecular formula of following using criss- cross method.i. Magnesium oxide ii. Calcium carbonate.

Answer 1

Answer:

magnesium chloride:

We have to remember that the atomic number of Magnesium is  and has a valency of 2. It means it has two electrons in the outermost shell for bonding. The atomic number of chlorine is  and has 7 electrons in the outermost shell. It means it just needs one more atom for bonding. Hence, we will use atoms of chlorine to bond with one atom of magnesium.

We can apply the criss-cross method for this compound as,

Mg2+ _          _   C1-

              _ _

   2   _ Mgc12  _     1

Therefore, the chemical formula of magnesium chloride is