Great question, let me know if you get the anwser!
The atomic mass is the average of the isotopes of the element meaning most averages of isotopes will not be whole numbers
The 2 in front of 
in 
is <u>Coefficient.</u>
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The 
after 
in the same equation is <u>sub </u><u>script</u><u>.</u>
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There are two atoms of in 
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Answer:
Francium (Fr)
Explanation:
Looking at the periodic table, Francium has 7 energy levels as it is in the 7th Period and is in the 1st Group (meaning it has one electron in the outermost shell) which suggests that it has one valence electron.
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1 wavelength, 2 crest, 3 trough, 4 wave height <3
