Answer:
Explanation:
The formula for sodium is Na. It does not form a molecule in some way.
1 mol Na = 6.02*10^23 atoms
3.91 mol = x Cross multiply
x = 3.91 * 6.02 * 10^23
x = 23.65 * 10^23
x = 2.365 * 10^24
Scientific notation is always expressed as a number 1 ≤ x < 10
