Question

Q10. An element has 3 electrons, 3 protons and 4 neutrons. What will be its atomic number and mass number? (​

Answer 1

Given info : An element has three electrons , three protons and four neutrons.

To find : the atomic number and mass number of the element are..

solution : no of electrons = 3

no of protons = 3

no of neutrons = 4

we know,

        atomic number = no of protons

        mass number = no of protons + no of neutrons

here atomic no of the element = no of protons in an atom of the element = 3

and mass number of the element = 3 + 4 = 7

[ note : as atomic number of element is 3, electronic configuration of it is 1s² , 2s¹

it is an S - block element. also the group of it is 1st and the period of it is 2nd. if you see that position in the modern periodic table, you will get the element and that is Lithium. ]