How to Find out the Most Abundant Isotope from the Standard Atomic Weight

The standard atomic weight is the weighted average (arithmetic mean) mass of the element; so, it's never an integer!


Isotopes are distinct nuclides (or nuclear species) of the same chemical element, E and have the same atomic number, Z (number of protons, p in their nuclei), but different nucleon numbers (mass numbers, A) due to different numbers of neutrons, n in their nuclei.

Question:

The standard atomic weight of Sr is 87.62. Given that there are only three naturally occurring isotopes of strontium, 86Sr, 87Sr, and 88Sr, which one is the most abundant isotope?

Solution:



Click/tap to enlarge the image

How is it❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Wikipedia Contributors. Standard atomic weight. Wikipedia.

(2)    Wikipedia Contributors. Isotope. Wikipedia. https://en.wikipedia.org/wiki/Isotope.

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