Question

Given that P-31 is the only natural isotope of phosphorus, what is the mass of one P atom and the mass of Avogadro's number of P atoms, respectively?

Answer 1

Answer:

Mass of Avogadro's number of P atoms = 31 g

Mass of 1 P atom = 5.15*10⁻²³ g

Explanation:

The two rules to consider are:

1) Mass of 1 mole of an element is equal to its molar mass in grams

2) 1 mole of any element contains Avogadro's number of atoms

i.e. 1 mole = 6.023*10^23 atoms(or molecules or particles)

For P-31

1 mole of P-31 = 31 grams

i.e. Mass of Avogadro's number of P atoms = 31 g

6.023*10^23 P atoms = 31 g

Therefore, mass of 1 P atom is:

$= \frac{1\ P\ atom *31\ g}{6.023*10^{23}\ atoms}=5.15*10^{-23}\ g$

Answer 2

The mass of on P atom would be 31 divided by 6.02 * 10^23
The mass of Avogadro's number of P atoms would be 31, since the atomic weight of and element is the mass of exactly one mole of that element, and Avogadro's number is the number of atoms in one mole.