Answer:
[tex]\boxed {\boxed {\sf About \ 92.2 \ moles \ of \ Magnesium}}[/tex]
Explanation:
To convert from atoms to moles, we must Avogadro's number:
This number tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case, it is atoms of magnesium in 1 mole.
- 6.022 *10²³ atoms Mg / 1 mol mg
Now, let's set up an expression using:
[tex]\frac {6.022 * 10^ {23} \ atoms \ Mg}{ 1 \ mol \ Mg}[/tex]
Multiply this by the given number of atoms.
[tex]5.55*10^{25} \ atoms \ Mg *\frac {6.022 * 10^ {23} \ atoms \ Mg}{ 1 \ mol \ Mg}[/tex]
Flip the fraction so the atoms of magnesium can cancel.
[tex]5.55*10^{25} \ atoms \ Mg *\frac { 1 \ mol \ Mg }{6.022 * 10^ {23} \ atoms \ Mg}[/tex]
[tex]5.55*10^{25} *\frac { 1 \ mol \ Mg }{6.022 * 10^ {23}}[/tex]
Multiply and condense this into 1 fraction.
[tex]\frac { 5.55*10^{25} \ mol \ Mg }{6.022 * 10^ {23}}[/tex]
[tex]92.1620724 \ mol \ Mg[/tex]
The original measurement had 3 significant figures, so our answer must have that many as well. For the number we calculated, that is the tenth place. The 6 in the hundredth place tells us to round the 1 to a 2.
[tex]92.2 \ mol \ Mg[/tex]
It is about 92.2 moles of magnesium.
