📖 what
What is isotopic abundance?
Quick Answer
Isotopic abundance is the proportion of each isotope of an element found in a natural sample. It is why many atomic masses on the periodic table are not whole numbers.
The Full Story
Most elements occur as mixtures of isotopes, which are atoms of the same element with different numbers of neutrons. Each isotope can occur in a different percentage in nature. For example, chlorine naturally consists mostly of chlorine-35 and chlorine-37, and the average of those isotopes gives chlorine’s listed atomic mass. This average is called the relative atomic mass or standard atomic weight in many contexts.
Key Facts
1.Isotopes have the same number of protons but different numbers of neutrons
2.Natural atomic masses are often weighted averages
3.Chlorine has two common stable isotopes
YouTube Angle
Suggested video title for this topic:
"Why the periodic table often shows decimal atomic masses"
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