Density equal mass/volume
so you would have 84.96/4.35= 19.5310345
i hope i remembered this right
A picture. hope this helps at least a little.
No. Of protons = mass no. - no. Of neutrons
No. Of protons = 67 - 37
= 30
No. Of electrons = 28
Zinc will have 30 protons and 28 electrons. So, it will have +2 charge
Symbol - Zn^+2
Oxid # : 0 0 +2 -1

∴ the nickel was oxidized while chlorine was reduced
nickel reduction potential = - 0.25 V
but since it is being oxidised the you have to switch the integer sign so the
the potential of nickel in this case becomes + 0.25 V
chlorine was reduced thus its reduction potential remains same = + 1.36 V
Overall Cell potential = ∑ of half cell potential
The overall cell potential = (+ 1.36) + (+ 0.25)
= + 1.61 V
∴
the answer would be D
#48 might be (A) but in not for sure