1. How do you excite an electron?
In your own words describe why its better to describe the movement of electrons as an electron cloud rather than orbitals.
How do you excite an electron?

2. Electromagnetic Spectrum

3. Background Neils Bohr Danish Physicist Proposed a “planetary”
model of the atom
Theorized that
travel in orbits around
the nucleus

4. Electrons in Orbit?
Bohr suggested that electrons “jump” between energy levels (orbits)
When an atom absorbs or gives off energy, the electron jumps to a higher or lower orbit.
It absorbs energy as it moves up to a higher orbit
It gives off energy as it moves down to a lower orbit
This energy is given off as heat or light
This energy given off travels in the form of waves
Also called an emission of an photon

5. Emission of photon
Absorption of energy +

6. E5 E4
E – 0.54 E3
E – 0.85
E – 01.51 E2
E – 3.40 E1
E – 13.60 +

7. To calculate the amount of energy between energy levels:
Just subtract the initial energy state from the final.
E5 to E1:
_-.54______ - _-13.6___ = 13.06
E3 to E1:
_-1.51__- _-13.60___= 12.09
E4 to E2:
_-.85_-__-3.40__= 2.55
E5 to E2:
_-0.54__-_-3.40__= 2.86
410mn E5
434mn E4 E3
486mn E2
656mn E1 + E
E -3.40
_________________________________
E -1.51
E -0.85
E – 0.54

8. _________________________________ 400 500 600 700 E -0.85 E – 0.54
410mn E4
434mn E3
486mn E2
656mn E1 + E
E -3.40
E -1.51
_________________________________
E -0.85
E – 0.54 8

10. The Electromagnetic Spectrum You actually know more about it than you may think!
The electromagnetic spectrum (EM) is just a name that scientists give all the different types of radiation when they want to talk about them as a group.
Radiation is energy that travels and spreads out as it goes
visible light that comes from a lamp in your house
radio waves that come from a radio station
Hotter, more energetic objects and events create higher energy radiation than cool objects.

11. Wavelength is
the distance from crest to
crest of a wave
The frequency of a wave is the number of waves that pass a given point one second

12. Electron Energy The longer the wavelength the lower frequency
The shorter the wavelength the higher the frequency

13. The Electromagnetic Spectrum
Radio:
the same kind of energy that radio stations emit into the air
also emitted by stars and gases in space
Helps astronomers learn what they are made of.
Microwaves:
They will cook your popcorn in
just a few minutes!
Microwaves in space are used
by astronomers to learn about
the structure of nearby galaxies,
our own Milky Way!

14. Infrared:
Our skin emits infrared light
In space, Infrared light maps the dust between stars

15. The Electromagnetic Spectrum
Visible Light:
This is the only section of the EM that can be seen by our eyes.
Visible radiation is emitted by everything from fireflies to light bulbs to stars ... also by fast-moving particles hitting other particles.

16. The Electromagnetic Spectrum
Ultraviolet:
The Sun is a source of ultraviolet
(or UV) radiation
Stars and other "hot" objects in
space emit UV radiation.
X-rays:
Your doctor uses them to look at your bones and your dentist to look at your teeth.
Hot gases in the Universe also emit X-rays .

17. Gamma Rays:
Radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma-rays.
Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma-rays.