A chemical substance has the characteristics that it cannot be separated by physical methods. Seawater and milk can be separated by sedimentation, and air has different components depending on other aspects (such as elevation). Only ammonia is a substance. (thus it can have a formula: NH<span>3)</span>
they are made by of two types of elementary particles
electrons and quarks
quetion answered by
(jacemorris04)
DNA is one and Grow and Develop i think i could be wong let me know i can read up on it some more
