Question
(i) (a) Represent the change in the nucleus of a radioactive element when a $\beta$ particle is emitted.
(b) What is the name given to elements with same mass number and different atomic number?
(c) Under which conditions does the nucleus of an atom tend to be radioactive?
(ii) (a) State one harmful effect of the radioactivity.
(b) Name the radioactive radiations which have the least penetrating power.
(c) Give one use of radio isotopes.
(d) What is meant by background radiation?
(iii) The ore of Uranium found in nature contains ${ }_{92}^{238} U$ and ${ }_{92}^{235} U$. Although both the isotopes are fissionable, it is found out experimentally that one of the two isotopes is more easily fissionable.
(a) Name the isotope of Uranium which is easily fissionable.
(b) Give a reason for your answer
(c) Write a nuclear reaction when Uranium 238 emits an alpha particle to form a Thorium (Th) nucleus.
(b) What is the name given to elements with same mass number and different atomic number?
(c) Under which conditions does the nucleus of an atom tend to be radioactive?
(ii) (a) State one harmful effect of the radioactivity.
(b) Name the radioactive radiations which have the least penetrating power.
(c) Give one use of radio isotopes.
(d) What is meant by background radiation?
(iii) The ore of Uranium found in nature contains ${ }_{92}^{238} U$ and ${ }_{92}^{235} U$. Although both the isotopes are fissionable, it is found out experimentally that one of the two isotopes is more easily fissionable.
(a) Name the isotope of Uranium which is easily fissionable.
(b) Give a reason for your answer
(c) Write a nuclear reaction when Uranium 238 emits an alpha particle to form a Thorium (Th) nucleus.
