what will be the composition of the nucleus of the atom of an element with atomic number 19 and the mass number 39?also write its electronic configuration.

As the atomic number is the number of protons = 19

mass number = 39

So, no. of nuetrons = 39-19=20

Therefore the composition of the nucleus of the atom is 19 protons and 20 nuetrons.

electric configuration is the arrangement of the electrons in an atom

it will be 2,8,8,1