AIM: Models of the Atom DO NOW: Element Y has two isotopes: Y-27 and Y-29. Y-27 has an abundance of 43% and Y-29 has an abundance of 57%. What is the average.
Development of the Atom. Atomic Models A model uses familiar ideas to explain unfamiliar facts observed in nature. A model can be changed as new information.
Democritus This is the Greek philosopher Democritus who began the search for a description of matter more than 2400 years ago. This is the Greek philosopher.
