In nuclear fission heavier elements are split to make lighter elements whilst releasing energy. An atom, its nucleus to be more specific, is bombarded with neutrons. The nucleus becomes unstable and it starts to split/decay. It creates the fusion products. Neutrons and lighter elements are released; the neutrons from the nuclei of the atom(s) being split.
Answer: 4. 
and 
Explanation:
a) The given reaction is 
As the mass on both reactant and product side must be equal:
As the atomic number on both reactant and product side must be equal:
b) 
Total mass on reactant side = total mass on product side
15 =15 + x
x = 0
Total atomic number on reactant side = total atomic number on product side
8 = 7 + y
y = 1
Answer:
Krypton does not react with anything, but it reacts with fluorine gas
Explanation:
(4) Zirconium
This element is often used in the chemical production field, and as implants due to its high chemical resistance and stability.
Is bubble chamber one of your choices? Bubble chamber sounds like a good fit for the question.
