H2O is the chemical formula of water. It means that each molecule of water is made up of two hydrogen atoms, indicated by the letter H, and a single oxygen atom, represented by the O. Water is a chemical substance with no smell, taste, or color.
Answer:

Explanation:
1. Calculate the molar mass of Na₂SO₄

The molar mass of Na₂SO₄ is 142 g/mol.
2. Calculate the moles of Na₂SO₄

3. Calculate the mass of Na₂SO₄

First shell from the nucleus can have a maximum of 2 electrons ! hope this helped