Answer
a) $Na^{+}$
b) $Se^{2-}$
c) $Mn^{2+}$
d) $Au^{3+}$
e) $Sn^{4+}$
f) $Hg^{+}$
Work Step by Step
a) Sodium has the symbol Na. It forms ion with +1 charge.
b) Selenium has the symbol Se. It forms ion with -2 charge and it is called selenide ion.
c) Manganese has the symbol Mn. It forms ion with +2 charge.
d) Gold has the symbol Au and III represents that the ion is having +3 charge.
e) Tin has the symbol Sn and Stannous means $Sn^{2+}$ and Stannic means $Sn^{4+}$
f) Mercury has the symbol Hg and it forms mercurous ion with + 1 charge .
