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प्रश्न
What is nucleus of an atom? Compare its size with that of the atom. Name its constitutents. How is the number of these constituents determined by the atomic number its atomic model.
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उत्तर
The nucleus at the centre of atom, whose size is of the order of 10-15 m to 10-14 m.
The size of a nucleus is 10-5 to 10-4 times the size of an atom. It consists of protons and neutrons.
If Z is the atomic number and A is the mass number of an atom, then the atom contains Z number of electrons; Z number of protons and A - Z number of neutrons.
The atom is specified by the symbol \[\ce{^A_Z X}\] where X is the chemical symbol for the element.
संबंधित प्रश्न
Arrange α, β, and γ rays in ascending order with respect to their
1) Penetrating power.
2) Ionising power
3) Biological effect
A nucleus `""_11^24Na` emits a beta particle to change into Magnesium (Mg)
(i) Write the symbolic equation for the process.
(ii) What are numbers 24 and 11 called?
(iii) What is the general name of `""_12^24Mg `with respect to `""_11^24Na` ?
Give a scientific explanation.
When the radiation coming out from a certain radioactive substance is passed through an electric field, marks are found at three places on the photographic plate placed in its path.
What kind of change takes place in a nucleus when a β -particle is emitted?
In the following fig. shows a radioactive source S in a thick lead container. The radiations pass through an electric field between the plates P and Q. Complete the diagram to show the paths of α , β and γ radiations.
Why is the source S placed in a thick lead container?
A nucleus is \[\ce{^24_11 Na}\] β-radioactive.
Write the equation represent β-decay.
How is a cathode ray beam affected while passing through a magnetic field?
State three ways of obtaining an electron-beam.
Two radioactive materials A and B have decay constants 25λ and 16λ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of B to that of A will be "e" after a time `1/("a"lambda)` The value of a ______.
When an α-particle of mass m moving with velocity ν bombards on a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on m as:
