1.   Where can I find detailed step by step instructions on how to build a Nitrogen (N₂) laser?

The following equation represents a fission reaction that takes place in power station reactors:

¹n₀ + ²³⁵U₉₂ = ⁹⁴Kr₃₆ + ^ABa_Z + 2(¹n₀) + energy

Name and explain the significance of A and Z. (4 marks)
State their numerical values. (2 marks)

Explain what is meant by the terms:
Isotope,
Atomic number,
Mass number. (6 marks)

Chadwick in 1932 was credited with the discovery of the neutron. He bombarded beryllium with alpha particles from the radioactive decay of polonium.

Complete the nuclear equation for the radioactive decay of polonium. ( 2 marks)
²¹⁰Po₈₄ = Pb + alpha
These alpha particles then struck beryllium nuclei that were at rest. The following reaction then took place:
⁴alpha₂ + ⁹Be₄ = ¹²C₆ + ¹n₀
Data for the reaction
Mass of Be nucleus = 9.012180 u; Mass of alpha particle = 4.002603 u; Mass of C nucleus = 12.00000 u; Mass of n = 1.008665 u; Kinetic energy of each alpha particle = 5.30 MeV

Use the data above to calculate:

The kinetic energy of the alpha particle in joules. (2 marks)
The energy liberated by each reaction in joules. (2 marks)
The total kinetic energy of the particles after the reaction. (1 mark)
The speed of the neutrons. You can assume that the neutron recieve much more energy than the more massive carbon nucleus.(2 marks)
Explain why you would expect the neutrons to have a sligtly lower speed than given by your calculation above. (1)