How many atoms are there in 10.2 moles of Phosphorous?

There are 2.06 x 10²⁴ atoms

The mole is the number of particles (atoms, molecules, ions)contained in a substance

1 mol = 6.02.10²³  particles

Moles can also be determined from the amount of substance mass and its molar mass

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the answer is c i believe