Answer:
[tex]Amount\ of\ Grams = 0.2644 g[/tex]
Explanation:
Given
Element: Sodium
[tex]Atoms = 6.92 * 10^{21}[/tex]
Required
Determine the amount of grams
We start by solving for the number of moles
[tex]Moles = \frac{Sodium\ Atoms}{Avogadro\ Number}[/tex]
[tex]Avogadro\ Number = 6.022 * 10^{23}[/tex]
So, we have:
[tex]Moles = \frac{6.92 * 10^{21}}{6.022 * 10^{23}}[/tex]
[tex]Moles = \frac{6.92 * 10^{21-23}}{6.022}[/tex]
[tex]Moles = \frac{6.92 * 10^{-2}}{6.022}[/tex]
[tex]Moles = 1.15 * 10^{-2}[/tex] moles
Next, we calculate the amount of grams.
Mass per mol of Sodium = 22.98977g/mol
For [tex]1.15 * 10^{-2}[/tex] moles of sodium
[tex]Amount\ of\ Grams = 1.15 * 10^{-2}\ mol * 22.98977g/mol[/tex]
[tex]Amount\ of\ Grams = 1.15 * 10^{-2} * 22.98977g[/tex]
[tex]Amount\ of\ Grams = 0.264382355 g[/tex]
[tex]Amount\ of\ Grams = 0.2644 g[/tex] (approximated)
Hence, there are 0.2644g of sodium in [tex]6.92 * 10^{21}[/tex] atoms
