What were the drawbacks of Rutherford's model of an atom?

Write the names of three elementary particles which constitute an atom. Which of these particles determine the mass of an atom? Justify your answer with an example.

An ion $X^{2-}$ contains $10$ electrons and $8$ neutrons. What are the atomic number and mass number of element $X$?

An atom with $3$ protons and $4$ neutrons will have a valency of

Rutherford's $\alpha$-particle scattering experiment showed that:
$(i)$ electrons have negative charge
$(ii)$ the mass and positive charge of the atom is concentrated in the nucleus
$(iii)$ neutron exists in the nucleus
$(iv)$ most of the space in the atom is empty
Which of the above statements are correct?

Find out the valency of the atoms represented by the Fig. $(a)$ and $(b)$.