Question 21N.1.hl.TZ0.4

Which species has two more neutrons than electrons?

${}_3{}^{6}L{i}^{+}$             ${}_4{}^{9}B{e}^{2+}$             ${}_{11}{}^{23}N{a}^{+}$             ${}_{20}{}^{42}C{a}^{2+}$

A.  ${}_3{}^{6}L{i}^{+}$

B.  ${}_4{}^{9}B{e}^{2+}$

C.  ${}_{11}{}^{23}N{a}^{+}$

D.  ${}_{20}{}^{42}C{a}^{2+}$