Who discovered the negatively charged sub-atomic particle?

1. Goldstein
2. Dalton
3. Chadwick
4. Thomson

What is the name of the scientist who discovered the presence of a positively charged particle in an atom?

Which sub-atomic particle was discovered by:

Thomson

Which sub-atomic particle was discovered by:

Goldstein

Which sub-atomic particle was discovered by:

Chadwick

J.Chadwick discovered a sub-atomic particle which has no charge but has mass nearly equal to that of a proton.

Name the particle and give its location in an atom.