A lithium atom has 3 electrons, 3 protons and 4 neutrons. Its mass number is:

(a) 3

(b) 4

(c) 7

(d) 10

Give two differences between nuclear fission and nuclear fusion.

A radioactive element is kept in an evacuated chamber. The rate of radioactive emission will: (a) decrease (b) increase (c) remain unchanged (d) depend on the temperature

A radioactive element P emits one α-particle and transforms to a new element Q. What will be the position of the element Q in the periodic table? (a) One group to the left of P (b) One group to the right of P (c) Two groups to the right of P (d) Two groups to the left of P

A radioactive nucleus containing 128 nucleons emits a β-particle. After β-emission the number of nucleons present in the nucleus will be: (a) 128 (b) 129 (c) 124 (d) 127

Which of the following radiations suffer maximum deflection in a magnetic field? (a) Alpha radiations (b) Beta radiations (c) Gamma radiations (d) X-radiations

(a) Which nuclear radiation will travel undeviated in an electric field? (b) How can one stop the radiations escaping from a nuclear reactor in a nuclear power plant? (c) Name one internal source of background radiations.

(a) Complete the following nuclear changes: (b) Name the nuclear radiation which has the highest ionizing power.

How is the radioactivity of a radio isotope affected if it undergoes a chemical change? Give a reason for your answer.

(a) When does the nucleus of an atom tend to become radioactive? (b) Name a single pulley in which displacement of load and effort is not the same. (c) State one advantage of this pulley.

Curium is a radioactive element with the symbol named in honour of Madam Curie. The graph of number of protons vs number of neutrons for some elements is shown below: (a) Which point on the graph indicates the element Cm? (b) Which point on the graph indicates daughter nucleus after Cm undergoes radioactive decay of 1α followed by 2β? (c) State the mass number of the daughter nucleus.

(a) Complete the following radioactive reaction: (b) Uranium is available in two forms U-235 and U-238. Which of the two isotopes of Uranium is more fissionable?

Copy and complete the nuclear reaction by filling in the blanks.