Mass of Cl₂ : 164.01 g
<h3>Further explanation</h3>
A mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
N = n x No
N = number of particles
n = mol
No = 6.02.10²³ = Avogadro's number
mol Cl₂ :

mass Cl₂(MW=71 g/mol) :

Each orbit surrounding an atom is allowed A LIMITED NUMBER OF ELECTRONS.
The number of orbit that an atom has is determined by its atomic number, the higher the atomic number the higher the number of orbit in the atom and each orbit has different energy level. Each orbit can only take fixed number of electron. The first shell can only take two electrons while the subsequent shells can only take eight electrons. When an orbit has taken the highest number of electron possible, the remaining electrons are moved to the next shell.