2. Schrödinger's/ Modern model of the atom

3. Particle-Wave Nature of Matter
Light has a particle nature (Einstein):
photon – quantum of energy that behaves in some ways like a particle
Matter has a wave nature (De Broglie):
Electrons scatter like X-rays
Electron microscopes use this property to see very small things.

4. Heisenberg’s Uncertainty Principle
The position and speed of a moving object cannot BOTH be known exactly at the same time.

5. Heisenberg, Cont. Why? The act of observing changes an object.
To see things, we must bounce light off of them.
To observe an electron, we have to bounce light off of it.
The light would move the electron so much that we would not be able to tell where it was, or how fast it was going.
Think of hot tea and a cold thermometer.

6. A new idea!
Orbitals:
A region around the nucleus of the atom where an electron of a given energy is likely to be found.
We don’t know exactly where electrons really are, just where they are likely to be.
Also called an electron cloud or probability region.

7. So, what’s an orbital?? Orbit  Orbital
ex. Electron is like a bee around a beehive.