Question

An element's atomic number is 40. How many electrons would an atom of this element have?

An atom of element A has 111 protons. What would the element's atomic number be?

How many neutrons does an element have if its atomic number is 55 and its mass number is 161?

Answer 1

Hello my friend,
since atomic no. = no. of electrons
there will be 40 electrons in that atom.
if and element has 111 protons, atomic no. will be 111.
no. of neutron = 161 - 55 = 106 neutrons.