To study the age of excavated materials of archeological significance, we study the rate of decay of an isotope of :

1. uranium
2. cobalt
3. carbon
4. chlorine

A radioactive nucleus emits a beta particle. The position of daughter nucleus in the periodic table as compared to the parent nucleus after emitting a beta particle is :

1. at the same place
2. one place higher
3. one place lower
4. two places lower

The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter nucleus is :

1. isotope of the parent
2. isobar of the parent
3. isotone of the parent
4. None of the above

The electron emitted in beta radiation originates from :

1. outer orbit of the atom
2. inner orbit of the atom
3. free electron existing in the nucleus
4. decay of the neutron in the nucleus