In the middle 1900s, chemists learned to make synthetic rubber, which became a substitute for most natural rubber in chewing gums. Most gums are made from a synthetic rubber, or a mixture of artificial and natural bases.

May is the fifth month of the year and have a length of 31 days.

Trees release oxygen when they use energy from sunlight to make glucose from carbon dioxide and water.  It takes six molecules of CO2 to produce one molecule of glucose by photosynthesis, and six molecules of oxygen are released as a by-product.

For the same reason that you are larger than your brain: electrons are components of molecules.