Question

Define mass number and atomic number. How are these represented around the symbol of an

element? The mass number and atomic number of an isotope of uranium (U) are 235 and 92

respectively. Calculate the number of protons and neutrons in the nucleus of the atom.

Answer 1

Atomic no is the no of protons present inside nucleus of an atom or no of electrons present in an atom

Mass no is the sum of no of protons and neutrons present inside nucleus of an atom.

mass no of uranium-235
atomic no-92

so no of protons-92
no of electrons-92
and
no of neutrons=235-92
=143