1. Chem

2. What do these 6 items all have in common?

3. Electromagnetic radiation
- a form of energy that has wavelike properties
- all forms found in the electromagnetic spectrum
Examples of electromagnetic radiation:
Xrays
Microwaves
Light waves
Radio waves – when you hear static on the radio when you aren’t getting a signal, that is the leftover microwaves from the big bang 15 billion years ago (it is cooling off so now the waves are the energy and wavelength of radio waves)

4. ELECTROMAGNETIC RADIATION
RADIO
WAVES
MICRO-
WAVES
INFRARED
LIGHT
VISIBLE
LIGHT UV
LIGHT
X-RAYS
LOWEST
ENERGY
HIGHEST
ENERGY

5. Listening to music in the car using the radio
RADIO WAVES
Listening to music in the car using the radio

6. MICROWAVES
Making popcorn

7. Using the remote control
INFRARED LIGHT
Using the remote control

8. The blue color of the sky
VISIBLE LIGHT
The blue color of the sky

9. ULTRAVIOLET LIGHT
Using a tanning booth

10. X-RAYS
Checking to see if the
ankle was broken

12. WAVELENGTH AND FREQUENCY ARE TWO IMPORTANT PROPERTIES OF WAVES.
DIFFERENT FORMS OF EMR TRAVEL IN WAVES.
WAVELENGTH AND FREQUENCY ARE TWO IMPORTANT PROPERTIES OF WAVES.

13. Wave Characteristics Amplitude Wavelength Wavelength
2 sec
0 sec
Amplitude
Wavelength
Wavelength
Frequency
Amplitude
The shortest distance between two equivalent
Points (meters)
How many waves pass a certain point per sec. (s-1 OR Hz)
Wavelength – the shortest distance between two equivalent points on a wave
Frequency – how many wave pass a certain point per second
Amplitidude –the height of the wave from crest to origin
State: Light travels as photons; photons have no mass but have energy
The energy a photon has is based on the equation E = hv
Energy is directly proportional to the frequency. Frequency has a unit of Hz which is = 1 𝑠 or s-1 or per second.
Wavelength is also related to frequency; how many people know the speed of light? Yes, what is it? EA 3 x 108 m/s
The speed of light is a constant that is known. Speed of light is based on the speed it travels over time. Wavelength is in meters and frequency is per second, so c=vλ
The height of a wave from crest to origin

14. THE HIGHER THE FREQUENCY, THE SHORTER THE WAVELENGTH
FREQUENCY = THE NUMBER OF WAVES THAT PASS BY A FIXED POINT PER SECOND.
THE HIGHER THE FREQUENCY, THE
SHORTER THE WAVELENGTH

15. THE HIGHER THE FREQUENCY, THE HIGHER THE ENERGY
FREQUENCY = THE NUMBER OF WAVES THAT PASS BY A FIXED POINT PER SECOND.
THE HIGHER THE FREQUENCY, THE HIGHER THE ENERGY

16. THE HIGHER THE ENERGY, THE SHORTER (SMALLER) THE WAVELENGTH

17. Practice

18. Electrons and Energy Levels
Each electron has a distinct amount of energy that is related to the energy level (shell) it is in
Electrons with the lowest energy are found in the shell closest to the nucleus
Electrons with the highest energy are found in the shell furthest from the nucleus
The greater the distance from the nucleus, the greater the energy of the electron

19. Each energy level has a maximum number of electrons that it can hold
The smallest energy level (the one closest to the nucleus, the first) can hold 2 electrons.
The second energy level, can accommodate 8 electrons.
The third energy level, can accommodate 18 electrons.
The 4th energy level can accommodate 32 electrons
N e
1 2
2 8
3 18
4 32

20. HOW DOES A NEON SIGN WORK?
BECAUSE OF ELECTRONS

21. Ground vs. Excited State
Ground state=when the electrons occupy the lowest energy levels possible
Excited state= on or more electrons gain energy and move to a higher energy level or shell (leaving the lower energy levels to be not completely full)

22. Ground and Excited State
When an electron gains energy, it jumps to a higher energy level or shell
This is a very unstable condition
We call this condition the excited state
Very rapidly, an electron in the excited state will lose energy and move back to a lower energy level or shell
When excited electrons fall from an excited state to a lower energy level, they release energy in the form of light

23. Ground  Excited State
Electron gains energy from heat, light, electricity
Electron “jumped” to a higher energy level (shell)

24. Excited  Ground State Electron releases energy in the form of light
Electron “falls” back and returns to ground state (normal position)

25. Bright Line Spectrum
Electrons falling from an excited state down to the ground state give off visible light
Different elements produce different colors of light or spectra
These spectra are unique for each element (just like a human fingerprint is unique to each person)

26. Demo