Question

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

Answer 1

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

Answer 2

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}`