Question

question 7

1. what is the mass of 8.2·10²⁶ atoms of lithium?

g li

Explanation:

Step1: Calculate the number of moles of Li

Use the formula \(n=\frac{N}{N_{A}}\), where \(N = 8.2\times10^{26}\) atoms and \(N_{A}=6.022\times 10^{23}\text{ atoms/mol}\).
\(n=\frac{8.2\times 10^{26}\text{ atoms}}{6.022\times 10^{23}\text{ atoms/mol}}\approx1362\text{ mol}\)

Step2: Calculate the mass of Li

The molar mass of \(Li\) (\(M\)) is \(6.94\text{ g/mol}\). Use the formula \(m = n\times M\).
\(m=1362\text{ mol}\times6.94\text{ g/mol}\approx9452\text{ g}\)

Answer:

\(9452\)