Table salt (NaCl) is composed of 60.66% chloride by mass. Here's how to calculate that:

* Molar Mass of Sodium (Na): 22.99 g/mol

* Molar Mass of Chloride (Cl): 35.45 g/mol

* Molar Mass of Sodium Chloride (NaCl): 58.44 g/mol

Calculation:

1. Mass of Chloride in NaCl: 35.45 g/mol

2. Percentage of Chloride in NaCl: (35.45 g/mol / 58.44 g/mol) * 100% = 60.66%