Atomic Nucleus:

• His entire positive charge of the atom and about 99.9 percent of its mass is concentrated in the nucleus.
• The radius of the atom is 105 times the radius of nucleus.
• The total charge of any nucleus is Ze. e indicates charge on one proton and Z is number of protons atomic no.
•  has 92 protons while number of neutrons N is a given by the equation N = A – Z = 235 – 92 = 143.
• The number of neutron and protons in the initial light element of the periodic table is almost equal bud in the later heavy element the number of neutrons is greater than the number of protons in the nucleus.