S1 : One of the many young scientists who chose to throw in their lot with Rutherford was an Oxford physical chemist, Frederick Soddy.

S6 : We now know that Gamma rays are a particularly fierce form of X-rays.

P : His association with Rutherford lasted only two years, but that was long enough to change the whole face of physics.

Q : He was just 23.

R : They found that thorium changed into a new element, thorium X, and in the process gave off what was apparently a gas and at the same time a third type of ray, which they named after the Greek letter ‘Gamma’.

S : When he teamed up with Rutherford, they investigated thorium which, as Marie Curie had shown, was radioactive.

The proper sequence should be