How many moles of tungsten atoms are in 4.8 * 10^25 atoms of tungsten?
Avogadro's number is the number of particles that we have in one mol of particles. It is 6.022 *10^23. For example: in 1 mol of atoms there are 6.022*10^23 atoms.
It's like a dozen. When we say a dozen atoms, we mean 12 atoms. So, when we say a mol of tungsten atoms, we mean 6.022 *10^23 atoms of tungsten.
1 mol of atoms of tungsten = 6.022 *10^23 atoms of tungsten
We will use that relationship to find the number of moles of tungsten atoms that we have in 4.8 *10^25 atoms of tungsten.
number of moles of tungsten atoms = 4.8 *10^25 atoms * 1 mol of atoms/(6.022 *10^23 atoms)
number of moles of tungsten atoms = 79.7 moles = 8 *10^1 moles
number of moles of tunsten atoms = 8.10^1 moles
Answer: b) 8*10¹ moles