# What is the number of representative particles in 7.50 mol SO_2?

The mole is simply a number, ${N}_{A}$ $=$ $6.022140857 \times {10}^{23} \cdot m o {l}^{-} 1$
So if there are $7.50$ $m o l$ $S {O}_{2}$ molecules; there are $7.5 \times {N}_{A}$ individual $S {O}_{2}$ molecules, and in that quantity there are $7.5 \times {N}_{A}$ individual $S$ ATOMS, and $15 \times {N}_{A}$ individual $O$ atoms. Are you with me?
We can use this number to specify the mass of the sulfur dioxide, because each of those individual particles has a definite and measurable mass, and this mass appears on the Periodic Table. Thus $1$ $m o l$ $S {O}_{2}$ has a mass of $32.06 \cdot g + 2 \times 15.999 \cdot g$, approx. $64$ $g$.
Can you tell the number of representative particles in a molar quantity of $S {O}_{3}$ gas? How many sulfur atoms? How many oxygen atoms.