(i) Explain the structure of an atom bomb.

Explanation

Principle :
`**` Uncontrolled chain reaction
`**` Release large amount of energy in short time
Structure :
`**` Fissile material whose mass is sub-critial
`**` Cylindrical fissile material is fit into void.
`**` Cylinder is injected into the void, using conventional explosive
`**` Two pieces together to form super - critical mass, leads to explosion.
`**` Tremendous amount of energy is released in the form of heat, light and radiation.
`** gamma` radiation, affects the living creatures.
`**` This type of atom bombs were exploded at Hiroshima and Nagasaki in Japan during Second World War.
(ii) `[H^+] = 1.0 xx 10^(-4) m, pH = ?`
`pH = -log_(10)[H^+]`
`= -log_(10) 1 xx 10^(-4)`
`[M^+] = -log_(10)^(1) - log_(10)^(10^(-4))`
`= 0 - (-4) log_(10)^(10) " " :. log_(10)^(10) = 1`
`pH 4`.