Q.Complete the following information about the isotopes in the chart given below (columns to fill: Mass Number, Number of Protons, Neutrons, Electrons):
Carbon-14
Lead-208
Chlorine-35
Uranium-238
Oxygen-18
Radium-223
(Hint: Refer to Periodic Table if required)

The atomic number, symbol Z, is the number of protons in an atom's nucleus, and it is what fixes the chemical identity of an element — every atom of the same element has the same Z. Since an atom is electrically neutral overall, and its positive charge comes entirely from Z protons, it must also carry exactly Z electrons outside the nucleus. The mass number, symbol A, is the TOTAL count of nucleons — protons plus neutrons — since protons and neutrons are the particles that contribute essentially all the measurable mass; the neutron count itself is written N. These three quantities are linked by $A = Z + N$, so $N = A - Z$. An atom's exact composition is written using th …