Answer:
Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g)
Explanation:
The net reaction is Z n ( s ) + 2 H + ( a q ) → Z n 2 + ( a q ) + H 2 ( g ) The C l − ions are spectators - they don't change.
Answer:
Specific gravity of mercury is 13.56 and it is an unit-less quantity.
Explanation:
Mass of the mercury = m = 607.0 lb = 275330.344 g
1 lb = 453.592 g
Volume of the mercury = v = 

Density of the mercury = d=
d = 13.56 g/mL
Specific gravity of substance = Density of substance ÷ Density of water

Specific gravity of mercury :
(unit-less quantity)
It must be made of matter because anything and everything is made up of atoms. The other three options are made of atoms but they are also matter.