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A single atom of an element has 21 neutrons, 20 electrons, and 20 protons. Which element is it? K Zr Ca Sc

User PMorganCA
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Ca or also known as Calcium ....... Hope it helps, Have a nice day:)
User Uzyn
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Answer: Calcium

Step-by-step explanation: As the element contains 20 electrons and 20 protons, it contains equal number of positive and negative charges, and thus it is a neutral atom.

Atomic number of an element = number of protons = number of electrons = 20

Thus the element is Ca with atomic number 20.

Mass number of an element = number of electrons + number of neutrons= 20+21= 41

Thus the representation of the element is:
_Z^A\textrm{X}

Where X = chemical symbol

A = mass number

Z = atomic number

Thus the representation is
_(20)^(41)\textrm{Ca}

User Anthony Poon
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