Apentix/AP Chemistry/Unit 1: Atomic Structure and Properties/Question

AP Chemistrymediummcq1 pt

The average atomic mass of magnesium is 24.31 amu. What does this value tell you about magnesium's isotopes?

A.Mg-24 is the most abundant isotope

B.Mg-26 is the most abundant isotope

C.All magnesium atoms weigh 24.31 amu

D.Magnesium has only one isotope

Explanation

Core Concept

A weighted average of 24.31 sits just above 24, so Mg-24 dominates, with smaller contributions from Mg-25 and Mg-26. The average is closest to the most abundant isotope's mass.

Correct Answer

AMg-24 is the most abundant isotope

More Unit 1: Atomic Structure and Properties practice questions

Try a random question →

Practice more AP Chemistry questions with full explanations

Practice Unit 1: Atomic Structure and Properties Questions →