+2, because Beryllium is in the Group II of the periodic table.
Hope this helps!
Following are the chemical and structural formulae of said complex compound,
Converting the temperature, 295 K from Kelvin to Celsius scale:

Water has a boiling point of
and a melting point of 
When we compare water at two different temperatures,
we can say that water is in liquid form at both these temperatures as both of them are quite below the boiling temperature and above the melting temperature.
The temperature difference between water at the given two temperatures = 
Water at
is at a higher temperature and so is warmer than water at a lower temperature of
.