1. Molar Mass of Sodium

* The molar mass of sodium (Na) is approximately 22.99 g/mol. This means that one mole of sodium atoms weighs 22.99 grams.

2. Calculation

* Mass = Number of moles x Molar mass

* Mass = 9 moles x 22.99 g/mol

* Mass = 206.91 grams

Therefore, the mass of 9 moles of sodium is approximately 206.91 grams.