Advertisements
Advertisements
Question
If neutrons exert only attractive force, why don't we have a nucleus containing neutrons alone?
Advertisements
Solution
Nuclear forces are short range strong attractive forces that act between two proton-proton, neutron-proton and neutron-neutron pairs. Two protons have strong nuclear forces between them and also exert electrostatic repulsion on each other. However, electrostatic forces are long ranged and have very less effect as compared to the strong nuclear forces.
So, in a nucleus (that is very small in dimension), there's no such significance of repulsive force as compared to the strong attractive nuclear force. On the other hand, an atom contains electrons revolving around its nucleus. These electrons are kept in their orbit by the strong electrostatic force that is exerted on them by the protons present inside the nucleus. Hence, a nucleus contains protons as well as neutrons.
APPEARS IN
RELATED QUESTIONS
A nucleus with mass number A = 240 and BE/A = 7.6 MeV breaks into two fragments, each of A = 120 with BE/A = 8.5 MeV. Calculate the released energy.
Boron has two stable isotopes, `""_5^10"B"` and `""_5^11"B"`. Their respective masses are 10.01294 u and 11.00931 u, and the atomic mass of boron is 10.811 u. Find the abundances of `""_5^10"B"` and `""_5^11"B"`.
The three stable isotopes of neon: `""_10^20"Ne"`, `""_10^21"Ne"` and `""_10^22"Ne"` have respective abundances of 90.51%, 0.27% and 9.22%. The atomic masses of the three isotopes are 19.99 u, 20.99 u and 21.99 u, respectively. Obtain the average atomic mass of neon.
In a periodic table the average atomic mass of magnesium is given as 24.312 u. The average value is based on their relative natural abundance on earth. The three isotopes and their masses are `""_12^24Mg` (23.98504u), `""_12^25 Mg` (24.98584u) and `""_12^26Mg` (25.98259u). The natural abundance of `""_12^24 Mg` is 78.99% by mass. Calculate the abundances of other two isotopes.
Name a material which is used in making control rods in a nuclear reactor.
With the help of a suitable example and an equation, explain the term pair production.
Nuclear species or nuclides are shown by the notation ________ where X is the chemical symbol of the species.
\[\ce{^197_79Au}\] contains ______.
A nucleus of mass number A has a radius R such that ______.
A nucleus yYx emits one α and two β particles. The resulting nucleus is ______.
A nuclide 1 is said to be the mirror isobar of nuclide 2 if Z1 = N2 and Z2 = N1. (a) What nuclide is a mirror isobar of 1123 Na? (b) Which nuclide out of the two mirror isobars have greater binding energy and why?
Distinguish between isotopes and isobars.
Two nuclei may have the same radius, even though they contain different numbers of protons and neutrons. Explain.
Mass numbers of two nuclei are in the ratio of 4 : 3. Their nuclear densities will be in the ratio of ______.
What conclusion is drawn from Rutherford’s scattering experiment of α-particles?
Assertion (R): Fusion of hydrogen nuclei into helium nuclei is the source of energy of all stars.
Reason (R): In fusion heavier nuclei split to form lighter nuclei.
1 amu is defined as:
Energy equivalent of 1 amu is:
