1. Bell Ringer
Which question(s) did you find difficult on the test yesterday?
Today you will write about one page of Cornell notes, then you will need a separate sheet of paper for an exit slip.

2. What we’ve learned so far…
Atoms are made of protons, neutrons and electrons
Protons determine the identity of the element
Neutrons determine the isotope
Protons and neutrons are located in the nucleus of the atom
…but what about those electrons?

3. Electrons in the Atom
November 4, 2010

4. Rutherford’s model of the atom:
Discovered:
Atom is mostly empty space
Atom has a small, positively charged center (nucleus)
Problems:
How are electrons arranged?
Why don’t electrons crash into the nucleus?

5. How Does a Satellite Stay in Orbit?

6. Bohr Model
Electrons are arranged into specific orbitals around the nucleus
Electrons have different amounts of energy depending on the orbital they are in
Further away from nucleus = more energy
Closer to nucleus = less energy

7. Check for Understanding:
In your notes: rank the following electrons from lowest energy to higher energy 1
Energy increases as you move AWAY from the nucleus 4 4 3 1 2 3 2

8. Electrons can move! Atoms can absorb energy or emit energy
Absorb energy  electrons move to higher orbitals
Release energy  electrons move to lower orbitals

9. Light Energy absorbed/released by atoms can be in the form of light
Colors of light: ROY G. BIV
Red = lower energy
Violet = higher energy

10. Energy Travels in Waves

11. How are atoms different?
Atoms of different elements have orbitals of different energies.
This means they can give off different colors of light!
Atomic emission spectrum: the unique pattern of light emitted by a specific atom

12. Check for Understanding
The atomic emission spectrum of an atom is given below. Identify which element it is in your notes using the known spectra below.
Which element am I???
Krypton
Helium
Hydrogen
Xenon

13. How do scientists know what stars are made of?
Stars are far away and extremely hot, so we can’t take direct samples of gas!
Scientists look at the light given off by the star
Spectrum of light from the Sun
neon
helium
hydrogen

14. Exit Slip
For credit today, copy and complete the following questions on a separate sheet of paper using your notes:
Electrons are arranged in ____________ around the nucleus.
How does the energy of orbitals change as you move away from the nucleus?
Atoms _____________ energy when electrons move to higher orbitals.
Atoms _______________ energy when electrons move to lower orbitals
Purple light is __________________ in energy than red light.
What is an atomic emission spectrum?