<u><em>Answer:</em></u>
- The correct answer is Se^2-
<u><em>Explanation:</em></u>
- The elements of group VI-A are
- O, S, Se and Te.
- -2 is most likely form in groups VI-A elemenst like O^2- as well as S^2-. Similarly Se also have Se^2-.
<u><em>Reason:</em></u>
- Actually these elements have 6 valence shell electrons and they want to get 2 more electrons in order to get nearest configuration of noble gases.
In order to answer this, we mus know the data for the heat of combustion of propane. This is an empirical data that you can search online. The heat of combustion is -2220 kJ/mol. The molar mass of propane of 44.1 g/mol. The solution is as follows:
ΔH = -2220 kJ/mol (1 mol/44.1 g)(1000g/1kg)(20 kg)
<em>ΔH = -1006802.721 kJ or -1 GJ</em>
The answer is B
Hope this helped. Good luck!
Answer: Divide the mass of the object by its volume to yield the density of the object. For example, the object density = mass / (Vf – Vi). Compare the measured density to that of pure gold (19.3 g/cc) to determine whether the object is made of pure gold.
Explanation: I searched it
