Topic Menu

Cyber-chess a chess instruction site

E = mc2 - mass energy conversion

Q4.

(a)

(i) Copy and complete the equation below to represent the emission of an α particle by a isotope.

(ii) Calculate the energy released when a isotope nucleus emits an alpha particle

mass of uranium 238 nucleus: 238.05076 u

mass of an alpha particle: 4.00260 u

mass of thorium 234 nucleus: 234.04357 u

(5 marks)

(b) decays sequentially by emitting α particles and β– particles, eventually forming , a stable isotope of lead.

(i) There are eight alpha particles in the sequence.

Calculate the number of β- particles in the sequence.

(ii) State the nuclear change that occurs during positron emission. Hence, explain why no positrons are emitted in this sequence.

(6 marks Max)

(Total 11 marks)