How many water molecules are there on Earth?
4.68 x 1046 molecules of water on Earth
It is widely known the fact that water covers 71% of the Earth’s surface and is vital for all known forms of life. There are approximately 4.68 x 1046 molecules of water on Earth. Believe it or not, the overall amount of water on our planet has remained the same for two billion years. It is interesting to know that in a 100-year period, a water molecule spends 98 years in the ocean, 20 months as ice, about 2 weeks in lakes and rivers, and less than a week in the atmosphere.