Question

how many electrons are in an atom with an atomic number of 20, an atomic mass of 45 and a charge + 2
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Answer 1

Atomic no. = 20

Therefore the element is calcium.

And 1 calcium atom contains 20 electron with electronic confriguation as 2,8,8,2.

If it will have a charge of +2 then there is loss of 2 electron ,therefore electron in Ca2+ ion in 18 electrons And no. of electrons do not depend on mass. Thank you:-):-)