Who thought fire was one of four elements? A. Marie Curie B. John Dalton O C. Robert Boyle D. Aristotle

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Most metamorphosis processes take place

How many grams are in one mole of lead?