Polarity and Boiling Point: The polarity of the molecules determines the forces of attraction between the molecules in the liquid state. Polar molecules are attracted by the opposite charge effect (the positive end of one molecule is attracted to the negative end of another molecule.
The five disadvantages of solar power. It's intermittent. Solar energy is only available when the sun is shining. It's low efficiency. It requires large areas of land. It's not completely free of environmental impact. Ultrapure polysilicon is now scarce. It's high cost.
Also, active solar devices don't function well in overcast, rainy or snowy weather. The major positives of solar power is that it can generate free or very inexpensive energy. They are also very low maintenance, and some systems are maintenance-free. Also, the solar energy market is advancing rapidly.