Advertisements
Advertisements
प्रश्न
Define the term radioactivity. Of the three normally occurring radioactive radiations:
(a) Which has a positive charge?
(b) Which is most penetrating?
(c) Which has no electric charge?
उत्तर
The phenomenon of spontaneous disintegration of an unstable nucleus of naturally occurring isotope accompanied by emission of active radiations a
particles, β particles and γ radiations is called radioactivity.
(a) α particles have positive charge.
(b) γ radiation is most penetrating.
( c) γ radiation has no electric charge.
APPEARS IN
संबंधित प्रश्न
Give one example of isobars.
A radioactive source emits three types of radiations. Name them.
(i) Name the radiations which are charged.
(ii) Name the radiations which are most penetrating.
(iii) Name the radiations which travel with the speed of light.
(iv) Name the radiations which have the largest mass.
Define bound electrons.
Define mass number of an element.
State two properties that a substance should possess when used as a thermionic emitter.
State three common properties of beta rays and cathode rays.
Heavy radioactive elements eventually turn into ______.
The count rate of activity of a radioactive sample of a very large population decreased from 1024 to 128 in 3 minutes. Then the rate of disintegration at the end of 5 minutes is ______.
The mean lives of a radioactive substance are 1620 and 405 years for β-emission and β-emission respectively. The time after which three fourth of a sample will decay if it is decaying both by β-emission and β-emission simultaneously will be ______ years.
(Take ln 2 = 0.693)
