The electron distribution in an aluminium atom is

An atom with atomic number $9$ and mass number $19$ will have the following constituents:

The presence of electrons outside the nucleus and the nucleus at the centre of the atom was suggested by:

$(a)$ Both helium and beryllium have two electrons in their valence shells. Helium is a noble gas whereas beryllium is a metal. Justify.
$(b)$ Hydrogen exists in three isotopic forms. Why are the isotopes of hydrogen chemically alike?

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?

In what way is the Rutherford's atomic model different from that of Thomson's atomic model?