Eg
How many Mg atoms are there in 0.764 moles of Mg?
atoms

Explanation:

We are asked to find how many atoms of magnesium are in 0.764 moles of magnesium.

We convert moles 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 magnesium. So, there are 6.022 × 10²³ atoms of magnesium in 1 mole of magnesium.

Convert using dimensional analysis and set up a conversion factor using Avogadro's Number.

We are converting 0.764 moles of magnesium to atoms, so we multiply by this value.

The units of moles of magnesium cancel.

The original value of moles (0.764) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 0 in the thousandth place tells us to leave the 0 in the hundredth place.

0.764 moles of magnesium contains approximately 4.60 × 10²³ atoms of magnesium.

gas

explanation:

smoke is the matter of a gas