What is the mass of 2.20 x 10^22 atoms of Xe?

Explanation:

To convert from atoms to grams, we must first convert atoms to moles, then moles to grams.

To convert from atoms to moles, we must use a special number called Avogadro's number. It tells us the number of particles in 1 mole. In this case, the particles are atoms of xenon.

We can write this number as a ratio or fraction.

Then, multiply by 2.20 * 10²² atoms.

We want the atoms of xenon to cancel, so we flip the fraction.

Now, we can multiply and the atoms of xenon will cancel.

Now, convert moles to grams. We need to find the molar mass of xenon, which is on the Periodic Table.

Now, use the molar mass as a ratio.

Multiply by the number of moles we found above.

The moles of xenon will cancel.

The 1 as a fraction is irrelevant, so we can just multiply.

The original number (2.20) had 3 significant figures (2,2, and 0). We must round to 3 sig figs, which is the hundredth place.

The 6 in the thousandths place tells us to round the 9 to a 0 in the hundredth place, which bumps the 7 to an 8. We must still leave the 0 though, because it is the third significant figure.

There are about 4.80 grams of xenon in 2.20 *10²² atoms.

it could be an electron