Answer:
Moon has to be in-between the Earth and the Sun.
2. Moon's umbra should sweep your place.
3. Latitude and longitude of your place should be within the befitting limits.
The major force between ethanol and rubbing alcohol is hydrogen bond. Hydrogen bond are intermolecular force that are weaker than covalent bond but holds atoms together in a molecules. For an hydrogen bond to be formed, a molecule must contain an hydrogen atom that will be bonded to one of the most electronegative element.
(does this belong in chemistry?)
anyways, the parent was most likely a kid who wanted privacy. they wanted something so they are giving it to their kids.