40 POINTS! WILL MARK BRAINLIEST!! Determine the mass in grams of 4.83 × 10²¹ atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)

Explanation:

We want to convert atoms of arsenic to mass in grams. We have to complete 3 steps.

The first step is converting atoms to moles. We use Avogadro's Number for this. This number is 6.022*10²³ and it is the number of representative units (molecules, atoms, etc.) in 1 mole of a substance. In this problem, the particles are atoms of arsenic. So, 1 mole of arsenic contains  6.022*10²³ atoms of arsenic. Use this information to make a ratio.

Multiply by the number of atoms provided in the problem: 4.83 × 10²¹

The units of atoms of arsenic (atoms As) cancel.

Condense into 1 fraction.

The next step is converting moles to grams. We use the molar mass for this, which is provided. There are 74.92 grams of arsenic in 1 mole of arsenic, so we can make another ratio.

Multiply by the number of moles we calculated.

The units of moles of arsenic (mol As) cancel.

The original measurement of atoms (4.83 × 10²¹ ) has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place (0.6009026901) tells us to round the 0 to a 1.

There are approximately 0.601 grams of arsenic.

b.final

the answer for sodium is 0.186

the answer for rubidium is 0.251