C) gamma radiation
There are three major types of particles emitted during a radioactive decay. These include: alpha, beta and gamma particles. Positrons are essentially positively charged beta particles
Alpha particles tend to be slow moving and heavy. Beta particles are similar to electrons while gamma particles are the lightest, fast moving and highly penetrating.
Actually the smallest radiation is not positron radiation, but gamma radiation :)
Answer : The radiation which is smallest in the size is, Gamma radiation.
Alpha particle : It is also known as alpha radiation or alpha ray that consists of 2 protons and 2 neutrons that are bound together into a particle that is identical to the helium nucleus. It is produced in the process of alpha decay.
Beta particle : It is also known as beta radiation or beta ray. During the beta decay process, a high energy and speed electron or positron are emitted by the radioactive decay of atomic nucleus.
Gamma particle : It is also a gamma radiation or gamma ray that is arising from the radioactive decay of atomic nuclei. It has shortest wavelength waves and imparts high photon energy can pass through most forms of matters because they have no mass.
The increasing order of the particle size of the alpha, beta and gamma particles will be :
Gamma particle < Beta particle < Alpha particle
Hence, the radiation which is smallest in the size is, Gamma radiation.
1. they vary with a higher number because boiling is way hotter than melting