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Course: High school chemistry > Unit 1

Lesson 2: Isotopes and ions
Science
High school chemistry
Atoms, elements, and the periodic table
Isotopes and ions
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Problem

Over 98% of all mined gallium is used in the electronics industry, where it’s found in mobile phones, Blu-ray lasers, and light-emitting diodes (LEDs).
A photograph of blue electronic L E D lights.
Gallium nitride LEDs
Gallium has only two stable isotopes: Ga-69 and Ga-71. The average atomic mass of gallium is 69.72 amu.
Gallium-based LEDs contain a mixture of these two naturally occurring isotopes.
Based on its average atomic mass, which isotope is more prevalent in a gallium LED?
Choose 1 answer: