112k views
4 votes
Calculate the mass, in grams, of 382 atoms of lithium, Li (1 mol of Li has a mass of 6.94 g).

1 Answer

7 votes

Final answer:

The mass of 382 atoms of lithium is 4.40 × 10^-20 grams. This is calculated by determining the number of moles those atoms represent and then applying the molar mass of lithium to find the mass in grams.

Step-by-step explanation:

To calculate the mass of 382 atoms of lithium (Li), we use the concept of molar mass, which is the mass of one mole of representative particles of a substance. We know that the molar mass of lithium is 6.94 g/mol, and that one mole contains 6.022 × 1023 atoms.

First, we need to find out how many moles 382 atoms represent. We can set up a proportion where 6.022 × 1023 atoms are to one mole, as 382 atoms are to x moles:


382 atoms × (1 mole / 6.022 × 1023 atoms) = 6.34 × 10-22 moles

Now, we will convert this number of moles into grams using the molar mass of lithium:


6.34 × 10-22 moles × (6.94 g/mol) = 4.40 × 10-20 grams

Therefore, the mass of 382 atoms of lithium is 4.40 × 10-20 grams.