Which scientist proposed the plum pudding model of the atom?

The $\alpha$-particle is the nucleus of an atom of

The diagram shows the path of four $\alpha$-particles of the same energy being scattered by the nucleus of an atom. Which of these is/are not physically possible?

An $\alpha$-particle of $5 \; MeV$ energy strikes a stationary uranium nucleus at a scattering angle of $180^o$. The distance of closest approach of the $\alpha$-particle to the nucleus will be of the order of:

Rutherford's $\alpha$-particle experiment showed that the atoms have

In $1911$,the physicist Ernest Rutherford discovered that atoms have a tiny,dense nucleus by shooting positively charged particles at a very thin gold foil. $A$ key physical property which led Rutherford to use gold was that it was