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प्रश्न
The mass number of a nucleus is
विकल्प
always less than its atomic number
always more than its atomic number
equal to its atomic number
sometimes more than and sometimes equal to its atomic number.
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उत्तर
sometimes more than and sometimes equal to its atomic number
Mass number of a nucleus is defined as the sum of the number of neutron and protons present in the nucleus, i.e. the number of nucleons in the nucleus, whereas atomic number is equal to the number of protons present. Therefore, the atomic number is smaller than the mass number. But in the nucleus (like that of hydrogen 1H1), only protons are present. Due to this, the mass number is equal to the atomic number.
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संबंधित प्रश्न
In the study of Geiger-Marsdon experiment on scattering of α particles by a thin foil of gold, draw the trajectory of α-particles in the coulomb field of target nucleus. Explain briefly how one gets the information on the size of the nucleus from this study.
From the relation R = R0 A1/3, where R0 is constant and A is the mass number of the nucleus, show that nuclear matter density is independent of A
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"`.
Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_88^226 "Ra"`.
Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,
`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.
Name a material which is used in making control rods in a nuclear reactor.
Write one balanced equation to show Emission of `beta^-` (i.e. a negative beta particle)
With the help of a suitable example and an equation, explain the term pair production.
The atomic mass of Uranium `""_92^238"U"` is 238.0508 u, while that of Thorium `""_90^234"Th"` is 234.0436u, and that of Helium `""_2^4"He"` "is 4.0026u. Alpha decay converts `""_92^238"U"` into `""_92^234"Th"` as, shown below:
`""_92^238"U" -> ( ""_90^234"Th" + ""_2^4"He" + "Energy" )`
All nuclides with same mass number A are called ______.
A vessel contains oil (density 0.8 g/cm3) over mercury (density 13.6 g/cm3). A sphere of homogeneous composition floats with half its volume immersed in mercury and the other half in oil. The density of the material of the sphere in g/cm3 is ______.
A nucleus yYx emits one α and two β particles. The resulting nucleus is ______.
The valance electrons in alkali metal is a:-
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?
What conclusion is drawn from Rutherford’s scattering experiment of α-particles?
What is ‘Pair production’?
A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding energy per nucleon of unfragmented nuclei is 7.6 MeV while that of fragments is 8.5 MeV. The total gain in the binding energy in the process is:
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about:
The density of nuclear matter is:
1 amu is defined as:
