Question

1. calcium has three different isotopes. one has a mass of 35.00 amu; another has a mass of 41.00 amu; and another has a mass of 40.00 amu. which isotope is the most abundant of the three?

Explanation:

Step1: Recall the concept of atomic mass and isotopic abundance

The atomic mass of an element is the weighted average of the masses of its isotopes. The isotope with a mass closest to the atomic mass of the element is the most abundant. The atomic mass of calcium is approximately 40.08 amu.

Step2: Compare the given isotopic masses with the atomic mass of calcium

• The mass of the first isotope is 35.00 amu. The difference from 40.08 amu is \(|40.08 - 35.00|= 5.08\) amu.
• The mass of the second isotope is 41.00 amu. The difference from 40.08 amu is \(|40.08 - 41.00| = 0.92\) amu.
• The mass of the third isotope is 40.00 amu. The difference from 40.08 amu is \(|40.08 - 40.00|=0.08\) amu.

Since the isotope with a mass of 40.00 amu has the smallest difference from the atomic mass of calcium (40.08 amu), it is the most abundant.

Answer:

The isotope with a mass of 40.00 amu.