Arrange the atoms and ions in order of increasing size?

Question

For each of the following sets of atoms and ions, arrange the memebers in order of increasing size:
(a) Se(2-), Te(2-), Se
(b) Co(3+), Fe(2+), Fe(3+)
(c) Ca, Ti(4+), Sc(3+)
(d) Be(2+), Na(+), Ne.

The numbers in the ( ) represent the number of electrons added or taken away.

I just want to check if my answers are right.
(a) Se < Se(2-) < Te(2-)
(b) Fe(3+) < Co(3+) < Fe(2+)
(c) Ti(4+) < Sc(3+) < Ca
(d) Be(2+) < Na(+) < Ne

Answer 1

b and d are not right.

b. - going across a row the atoms get smaller so Co is smaller than Fe
d - Na is in row 3 and is larger than Be and Ne which are in row 2

Answer 2

size of atoms increases from right to left on the period and from bottom to top on the groups if an ion has a charge it has a similar size to the atom with that standard number of electrons. so Co3+/Fe2+ Fe3+