Final answer:
There are approximately 2.089 × 10^23 atoms in 69.78 grams of Hg.
Step-by-step explanation:
The number of atoms in a given amount of a substance can be calculated using Avogadro's number and the molar mass of the substance.
In this case, we need to find the number of atoms in 69.78 grams of Hg (Mercury).
First, we calculate the number of moles of Hg using its molar mass:
Molar mass of Hg = 200.59 g/mol
Number of moles of Hg = 69.78 g / 200.59 g/mol ≈ 0.347 moles
Next, we use Avogadro's number (6.022 × 10^23) to find the number of atoms:
Number of atoms = Number of moles × Avogadro's number
Number of atoms = 0.347 moles × 6.022 × 10^23 atoms/mol ≈ 2.089 × 10^23 atoms
Therefore, there are approximately 2.089 × 10^23 atoms in 69.78 grams of Hg.
Learn more about Calculating the number of atoms in a given amount of a substance