1. | is not important because nuclear forces are short-ranged |
2. | is as important as electrostatic force for binding the two atoms |
3. | cancels the repulsive electrostatic force between the nuclei |
4. | is not important because oxygen nucleus have equal number of neutrons and protons |
1. | |
2. | . |
3. | is not related to the mass of the hydrogen atom. |
4. | magnitude of the potential energy of electron in the atom). |
1. | do not change for any type of radioactivity |
2. | change for and radioactivity but not for radioactivity |
3. | change for radioactivity but not for others |
4. | change for radioactivity but not for others |
1. | triton energy is less than that of a nucleus. |
2. | the electron created in the beta decay process cannot remain in the nucleus. |
3. | both the neutrons in Triton have to decay simultaneously resulting in a nucleus with protons, which is not a nucleus. |
4. | free neutrons decay due to external perturbations which is absent in the Triton nucleus. |
and denote the atomic masses of the parent and the daughter nuclei respectively in radioactive decay. The value for a decay is and that for a decay is If denotes the mass of an electron, then which of the following statements is correct?
1. | |
2. | |
3. | |
4. |
In a nuclear reactor, moderators slow down the neutrons which come out in a fission process. The moderator used have light nuclei. The heavy nuclei will not serve the purpose, because:
1. | they will break up |
2. | elastic collision of neutrons with heavy nuclei will not slow them down |
3. | the net weight of the reactor would be unbearably high |
4. | substances with heavy nuclei do not occur in the liquid or gaseous state at room temperature |
(a) | nuclear forces have short-range. |
(b) | nuclei are positively charged. |
(c) | the original nuclei must be completely ionized before fusion can take place. |
(d) | the original nuclei must first break up before combining with each other. |