A deuteron has the same charge as a proton but approximately twice the proton mass. Suppose deuterons are being accelerated in a cyclotron in an orbit of radius 75 cm at a frequency of 8.0 Mhz. What magnetic field is needed?

Elementary particles, also known as fundamental particles, are subatomic particles that are not made up of other particles. They are smaller than an atom and do not appear to be made up of a combination of more basic things. 
The Standard Model recognizes 17 distinct particles, including 12 fermions and five bosons.