What is the relationship between mass and volume of a substance

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons

What can be found in the ionosphere

28. which is not a reason that water is used to store spent fuel rods from nuclear power plants? water increases the speed of the chain reaction in the fuel rods. water protects nuclear power plant workers from the high temperature and radiation of the fuel rods. water acts as a radiation shield to reduce the radiation levels. water cools the spent rods. salts action