Question

an atom of an element contains 20 electrons and atomic mass 40. deduce the number of neutrons and electronic configuration ​

Answer 1

Number of Protons = atomic number = 20.

Therefore, number of protons = 20.

Number of electrons = number of protons = 20.

Number of neutrons = Mass number - number of protons = 40-20 = 20.

The only option states wrong about Ca is C.