Children, even those that are vaccinated, may develop rotavirus disease more than once. That is because neither natural infection with rotavirus nor rotavirus vaccination provides full immunity (protection) from future infections. Usually a personâs first infection with rotavirus causes the most severe symptoms.
Because molecules move quicker at higher temperature, causing them to collides more. Since they collides more, reaction occurs to be a lot faster to. And that's why things dissolve quicker in hot water than in room temperature water.
Detail of Water Evaporation and Boiling Nothing happens to the water molecules themselves, except that they move faster. Boiling is a physical change, not a chemical one. All that happens is the weak attractive forces between different water molecules are broken and individual molecules are turned into a gas, which is steam.