1. Waves are classified into two main types: mechanical waves and electromagnetic waves. 2. Mechanical waves require a medium to propagate and can be longitudinal or transverse, while electromagnetic waves can travel through a vacuum. 3. The electromagnetic spectrum arranges all electromagnetic waves from gamma rays to radio waves based on their frequency and wavelength. It includes gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves and radio waves.

1. CLASSIFICATION
OF WAVESWaves are classifieds according to their
nature.

2. 2 classifications of waves
–MECHANICAL WAVE
–ELECTROMAGNETIC WAVE

3. MECHANICAL WAVE
• Requires a medium to propagate.
• Mechanical waves maybe longitudinal or
transverse.
• e.g. sound waves, water wave, earthquake,
etc.

4. ELECTROMAGNETIC WAVE
• Can travel in a vacuum and in any medium.
• Electromagnetic waves are transverse wave.
• e.g. radio wave, heatwave, light wave,
microwave, etc.

5. ELECTROMAGNETIC WAVE
• In 1862, James Clark Maxwell
theorized the existence of
electromagnetic waves.
However, it was not until
1887, through the effort of
Heinrich Hertz, When those
waves( except light) were
observed.

6. ELECTROMAGNETIC SPECTRUM
• Describes the entire range of electromagnetic
radiation, arranged in order by their
frequencies or wavelengths.

8. GAMMA RAY
• Are emitted by radioactive materials like
Cobalt-60 and cesium-137.
• They are highly penetrating because of
their very short wavelengths, which range
from less than 10-14 m to 10-10 m.
• Gamma rays are used to detect cracks in
metals.
• exposure can cause cancer or even
mutation, they can also destroy cancer
cells in the process called radiotherapy.
• Paul Villard discovered gamma ray in
1900.

10. X-RAY
• Also known as then Roentgen wave
• Are a thousand times shorter than the
shortest visible light and has a lengths
ranging from 10-12 m to 10-18 m.
• X-rays are used in internal photography,
also used in airports security checks to
see inside of luggage.
• Exposure to X-ray can cause damage to
tissues and cancer.
• Wilhelm Conrad Roentgen discovered X-
Ray.

12. UV-RAY (Ultraviolet Ray)
• Has a wavelength range of 10-10 m
to 10-8 m.
• Main source of UV rays is the SUN,
other sources are special lumps used
in bank to detect fake money or bank
notes.
• Long Exposure to UV Ray can cause
burn, produces sun-tan, and can
cause skin cancer.
• Johann Wilhelm Ritter discovered UV-
Ray.

14. • Extends from short wave 4x0-7 m to 7.6X107 m.
• Is a part of the electromagnetic spectrum visible to our
unaided eye.
• Colors of light:
VISIBLE LIGHT
Red - 760 nm
Orange - 610 nm
Yellow - 590 nm
Green - 550 nm
Blue - 470 nm
Indigo - 440 nm
Violet - 410 nm

16. INFRARED RAYS
• Also known as heat wave
• Have longer wavelengths than red
light ranging from 7X10-7 m to 10-3
m.
• Used in remote control fro television,
old mobile phones, night vision
equipment, computers, laptops and
printers are also equipped with
infrared ray.
• Long use will lead to overheating.
• Discovered by Sir William Herschel in
1800.

18. R DIO WAVES
• Has the longest
electromagnetic wavelengths
ranging from 10-1 m to 104 m.
• Used in police radio
communication system,
military aircraft, radio and
television stations. Also used in
GPS, Bluetooth, and WiFi.
• Discovered by Henrich Hertz in
1887.

20. Unit Test
(1 whole sheet of paper)

21. TEST I
TRUE OR FALSE

22. 1. All waves can travel in a vacuum.
2. Waves are periodic disturbance.
3. Electromagnetic waves are longitudinal
wave.
4. Mechanical waves can travel in a vacuum
of space.
5. Water wave is example of mechanical
wave.

23. 6. Electromagnetic waves can pass through any
medium.
7. Both mechanical and electromagnetic wave need a
medium to propagate.
8. Electromagnetic spectrum is a chart that show the
electromagnetic radiation with their corresponding
wavelengths and frequency.
9. Waves are classified according to their movement
and nature.
10. X-Ray is an example of electromagnetic wave.

24. IDENTIFICATION
TEST II

25. 11. This wave is used in microwave ovens
12. Used to take photographs of internal body
bones, internal organs) and is also used in
airport security checks to see the inside of your
luggage
13. This wave’s main source is the sun.
14. This wave is recorded as the most penetrating
wave because of their very short wavelengths.
15. These are the longest of all electromagnetic
waves ranges from 10-1 m to 10 4m.

26. 16. This can cause sun tan, burn or even skin
cancer.
17. Used in GPS, Bluetooth, WiFi, and Police Radio
Security Systems.
18. This wave is used for night vision equipment,
TV remote control and is used in most
computers, printers and laptops.
19. This is the only wave that is visible to our
unaided eye.
20. Used to detect cracks in metal.

27. MUTIPLE CHOICE
TEST II

28. 21. He is the scientist who theorized the
existence of electromagnetic waves.
A. Paul Villard
B. Wilhelm Roentgen
C. James Clark Maxwell
D. William Herschel

29. 22. Infrared wave or heat wave is
discovered by _____________.
A. Paul Villard
B. William Herschel
C. Wilhelm Roentgen
D. James Clark Maxwell

30. 23. Who discovered x-ray?
A. Johann Wilhelm Ritter
B. William Herschel
C. Wilhelm Roentgen
D. Heinrich Hertz

31. 24. ________ discovered gamma ray in
1900.
A. Paul Villard
B. Wilhelm Roentgen
C. James Clark Maxwell
D. Heinrich Hertz

32. 25. He discovered the ultraviolet (UV) rays.
A. Paul Villard
B. Johann Wilhelm Ritter
C. James Clark Maxwell
D. Heinrich Hertz

33. 26. Which of the following has the
LONGEST wavelengths?
A. RED
B. VIOLET
C. GREEN
D. BLUE

34. 27. Which of the following has the
SHORTEST wavelengths?
A. UV RAY
B. VISIBLE LIGHT
C. X-RAY
D. INFRARED WAVE

35. 28. Which of the following has the
HIGHEST FREQUENCY?
A. UV RAY
B. RADIOWAVE
C. VISIBLE
D. X-RAY

36. 29. Which of the following has the LOWEST
FREQUENCY?
A. UV RAY
B. MICROWAVE
C. VISIBLE
D. GAMMA RAY

37. 30. Which of the following has the
SHORTEST WAVELENGTH?
A. UV RAY
B. MICROWAVE
C. VISIBLE
D. GAMMA RAY

38. TEST IV
LABELING

39. 31-35
• Draw and label a transverse
wave

40. 36-40
• Draw and label a longitudinal
wave

41. 41-50
• Draw and label an
electromagnetic spectrum with
their frequencies and
wavelengths