Please help with the following questions on Light & Modern Physics

6. ((d) Consider the fission of uranium-235 in accordance with the nuclear equation: 235 92 U+ 141 Kr + 3-1 Ba + 36 i) What are the values of the quantities labelled x and y in the reaction? ii) Calculate the energy released in a single fission reaction. [7) Symbol Atomic Mass (u) 235 , U 92 235.04393 x Kr 91.92620 36 141 Ba 140.91440 1. 00867 (e) Given that r. = 1.2 x 10-15m, estimate the radius of the 92 e 235 U nucleus. 13] 7. A radioactive sample contains 530 x 10-8g of nobelium-259, which has a half-life of 59 min. i) How many atoms of nobelium-259 are in the sample initially? ii) What is the initial activity of the sample? iii) What is the activity of the sample after 8h? (b) What is meant by total internal reflection of light? State the conditions under which it occurs. Define critical angle and explain how the critical angle for a material in air depends on its refractive index. [51 (c) A ray of light is incident on the face AC of a glass prism, n = 1.51 as shown in Figure 7.1. (Air) n = 1.00 Figure 7.1 n = 1.51 B iii) What is the angle of refraction at the surface AC? iv) What is the angle of incidence on the surface AB? [5]