Nucleus is a positively charged spherical body present in the center of atom. By various experiments and researchs, scientists have figured out various properties of nucleus. Among many properties of an atomic nucleus, some of the properties of nucleus are described below:
Composition of Nucleus:Nucleus is composed of protons and neutrons which are collectively called nucleons. These nucleons are bounded together by a energy called as binding energy. This binding energy of nucleus is responsible for the stability of an atom.
Nuclear Charge: The nucleus comprises of protons and neutrons. Since neutrons are chargeless particles, the charge of nucleus ls equal to the number of protons in the nucleus. i.e. Nuclear charge = +Zewhere, Z is the atomic number and e = 1.6×10-19 (electronic charge)
Nuclear Mass: The mass of the nucleus is called nuclear mass. Nuclear mass is equal to the sum of masses of protons and neutrons each of which has mass of one atomic mass unit (1 amu)1 amu = 1.66 × 10-27 Kg.If mp and mn are the masses of protons and neutrons respectively and N and Z be the numbers of protons and neutrons respectively, then Nuclear mass = Nmp + Zmn However, the experimental measurements show that real mass of nucleus is less than this theoretical mass. This difference in mass of nucleus is called mass defect.
Nuclear Shape and Size:Nucleus is supposed to be nearly spherical in shape. From the experimental observations, scientists have found that the radius of nucleus (R) is directly proportional to the one-third power of mass number (A).i.e. R = roA1/3 where, ro = 1.15 × 10-15m. Rutherford’s alpha particle scattering experiments showed that the radius of nucleus is in the order of 10-10m. So. volume of nucleus (V) is given by, V = 4/3 πR3 or, V = 4/3 πro3A
Nuclear Density:Nuclear density (ρ) is given by the ratio of nuclear mass to the nuclear volume. ρ = (nuclear mass)/(nuclear volume) ρ = (m × A)/(4/3 πR3) where, m is the mass of one nucleon
ρ = (3m)/(4πro3) Putting m = 1.66 × 10-27 and ro = 1.15 × 10-15, ρ = 2.7 × 1017 kgm-3 This shows that the density of nucleus is very high and is independent with atomic number. All the nuclei have approximately same density.
Nuclear Spin or Angular Momentum: Proton and neutron are in continuous motion in discrete quantized orbit. This orbital motion produces the nucleon with mechanical angular momentum. In addition to orbital motion, nucleons have internal angular momentum called spin. As a result, they posses angular momentum associated with orbital spin.
Disintegration of NucleusNeutron-Proton ratio also plays important role in imparting properties of nucleus. Higher will be the neutron-proton ratio in the nucleus, more unstable will be the atom and it disintegrates. Atoms having least neutron-proton ratio are most stable one and have maximum value of binding energy ( You may refer to: Binding Energy of Nucleus). During disintegration, radioactive radiation are produced from the nucleus of atom.
So, these are the properties of the nucleus. Feel free to comment below about your opinions or suggestions…..