Question

Pennyium has 2 isotopes, Pennyium-24 with an abundance of 67.5% and Pennyium-25 with an abundance of 32.5%. Find the AAM for Pennyium.

a) 24.0 amu

b) 24.5 amu

c) 25.0 amu

d) 25.5 amu

Answer 1

To find the average atomic mass (AAM) of Pennyium, we multiply the abundances of its isotopes by their respective masses and add the results together, yielding an AAM of approximately 24.5 amu.

Step-by-step explanation:

To calculate the average atomic mass (AAM) of Pennyium, which has two isotopes with given abundances, one can use the formula:

AAM = (fractional abundance of isotope 1 × mass of isotope 1) + (fractional abundance of isotope 2 × mass of isotope 2)

For Pennyium-24 and Pennyium-25, the calculations are as follows:

• (0.675 × 24 amu) + (0.325 × 25 amu)
• (16.2 amu) + (8.125 amu)
• 16.2 amu + 8.125 amu = 24.325 amu

Therefore, the average atomic mass of Pennyium would be closest to option b) 24.5 amu.