What is the isotopic atomic mass of an isotope if 9.7023 × 10²² atoms weighs 4.0256 g?

Question

Quizplus · Accepted Answer

First, we need to identify the element for which we are calculating the isotopic atomic mass. This information is not provided, so we cannot narrow down the answer choices based on the periodic table. However, we can use the given information to calculate the isotopic atomic mass.

We know that the weight of 9.7023 × 10^22 atoms is 4.0256 g. We can use this information to calculate the mass of one atom:

4.0256 g / (9.7023 × 10^22 atoms) = 4.139 × 10^-23 g/atom

The isotopic atomic mass is defined as the mass of one atom of the isotope relative to 1/12th the mass of a carbon-12 atom. Therefore, we can calculate the isotopic atomic mass using the following formula:

Isotopic atomic mass = (mass of one atom / mass of carbon-12 atom) x 12

We know the mass of one atom from the previous calculation, and the mass of a carbon-12 atom is defined as exactly 12 atomic mass units (amu).

Isotopic atomic mass = (4.139 × 10^-23 g/atom / 1.9926 × 10^-23 g/atom) x 12 ≈ 24.986 amu

Therefore, the best choice is C) 24.986 amu.

What Is the Isotopic Atomic Mass of an Isotope If