What is an atom Grade 10 ST What

What is an atom? Grade 10 ST

• What is an Atom? • Can an atom be broken into a smaller piece? • NO. Atoms are the smallest particles. • • • It cannot be divided chemically How small is the smallest particle? Some perspective: • A sheet of paper is a million atoms. . . THICK • A drop of water can contain 1022 atoms • . A period has a diameter of at least 50 trillion atoms lined up in a row

• Democritus • His theory stated that the smallest unit of mater was the atom! • Today we know this be true! • Like building blocks atoms come together to form all substances in our environment.

Atoms Atom from the greek atomos “indivisible” • Molecular Theory of Matter states that all matter is composed of small, fast moving particles called atoms. These atoms can join together to form molecules. • This theory is really thousands of individual theories that provide evidence for the whole theory. • Since the atom is too small to be seen even with the most powerful microscopes, scientists rely upon models to help us to understand the atom.

• Atomic Model • Much contemplation • As we continue to learn and make advancements scientists continue to make changes to the atomic model

• What do you think? • Compare each of the atomic models to an object in your everyday life. Be creative!