The total energy equation would be Kinetic energy+Potential energy
I believe it is
1.6x=2.7(x-1.8)
1.1x=2.7*1.8
x~4.4
4.4*1.6
~7.1m
you have to substitiute volume of the ballon
s alluded to in the other answers, salt refers to any ionic compound that doesn't have “oxides” in it. Table salt is sodium chloride. Going down the periodic table, the first column contains lithium, sodium, potassium, rubidium, cesium, and francium. This group (alkali metals) of atoms (and their corresponding positive ions) gets larger in the order shown above. Therefore, their ionic bonds with chloride (or any nonmetal) gets smaller. The trend of their corresponding compounds is a decreasing hardness, decreasing melting point, decreasing boiling point, and decreasing thermal stability. These are the major periodic trends of these corresponding compounds. Other metal ions generally have higher positive charges on them. This makes the ionic bonds considerably larger and you can probably surmise most of their corresponding properties listed above. However, the details of their lattice structures may cause the overall trend to vary.
Answer:
481.76 J/mol
133.33 K
Explanation:
= Avogadro's number = 
Change in enthalpy is given by

Entropy is given by

Latent heat of fusion is given by

The latent heat of fusion is 481.76 J/mol
Melting point is given by

Melting occurs at 133.33 K