Answer:
[tex]\boxed {\sf 5.63 \times 10^{24} \ atoms \ Li}}[/tex]
Explanation:
We are asked to find how many atoms are in 9.35 moles of lithium (Li)
Moles are converted to atoms using Avogadro's Number or 6.022×10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of lithium.
We convert using dimensional analysis, so we set up a conversion factor using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ atoms \ Li}{1 \ mol \ Li}[/tex]
We are converting 9.35 moles of lithium to atoms, so we multiply the conversion factor by this value.
[tex]9.35 \ mol \ Li *\frac {6.022 \times 10^{23} \ atoms \ Li}{1 \ mol \ Li}[/tex]
The units of moles of lithium cancel.
[tex]9.35 *\frac {6.022 \times 10^{23} \ atoms \ Li}{1 }[/tex]
[tex]9.35 *{6.022 \times 10^{23} \ atoms \ Li}[/tex]
[tex]5.63057\times10^{24} \ atoms \ Li[/tex]
The original value of moles (9.35) has 3 significant figures, so our answer must have the same. For the number we found that is the hundredth place. The 0 in the thousandth place tells us to leave the 3 in the hundredth place.
[tex]5.63 \times 10^[24} \ atoms \ Li[/tex]
9.35 moles of lithium contains approximately 5.63×10²⁴ atoms of lithium.
