So I would like to check some of my answers. I really appreciate any help

Question

1. Which of the following atoms or ions is diamagnetic; Cr Br Mn2+ B C4+ - I said C4+
2. Which of the following atoms or ions is paramagnetic?
C4- S^4+ V^4+ Se2- Ge4+I said V^4+
3.Which one of the following elements has a +2 ion with 3 unpaired electrons?
Mg S V Se Mn- I said V
4.Use periodic trends and predict which of the following elements has the largest first ionization
energy.
Sr Cl Cs Br; I said Cl
5.Use periodic trends and predict which of the following elements has the smallest atomic radius.
Ar Sr Al Ne- I said Ne
6.Use periodic trends and predict which of the following ions has the largest radius.
O2-
N3-
Al3+
Mg2+; I got Mg^2+
7.Use the noble-gas notation and write the ground-state electronic configurations of the following ions:
(a) N3- (b) Tl3+ (c) Fe3+; a)(Ne) b) (Xe)4f155d10 c)(Ar)3d5
Each of the following oxides reacts with water to produce an acid or a base, depending on whether
the oxide is an acidic or a basic oxide. Give the formula of the product of this reaction.
(a) Cl2O7 (I got HCLO4) (b) Rb2O (RbOH) (c) SO3 (H2SO4)
I would be really grateful if you could verify please! You do not need to confirm all of them, even a small amount would be helpful!