Answer:
3.09 x 10²⁰ atoms
Step-by-step explanation:
We want to find the number of atoms in 20.5mg of argon.
We can use dimensional analysis to do so.
See attached image for table.
Needed conversions:
- 1g = 1000mg
- 1 mol of Ag = 39.948g
- 1 mol = 6.022 x 10¹³ atoms