Quarter 2 Science

• electromagnetic waves

  • waves that travels through the vacuum of outer space
  • formed when electric fields joined a magnetic field
• Magnetic and electric fields of an electromagnetic waves are perpendicular to each other and to the direction of the waves
• What will happen if electric charge vibrates?

  the electric field around it changes, creating a changing magnetic field.
• electric and magnetic fields vibrates at right angles to the direction the wave travels.

  This is called transverse waves.
• Hoe does EM waves travels?

  it travels in all direction.
• Where do EM waves travel fastest and slowest?

  It travels fastest in gas and slowest in solid,
• enumerate the properties of electromagnetic waves?

  • EM waves are transverse
  • Don't require any medium to travel
  • Travel at a speed of 3 x 10 ^-8 in vacuum
  • Can be reflected or refracted
  • Can be emitted or absorb by matter
• Arrange Electromagnetic Spectrum from longest to shortest wavelength

  1. Radio waves
  2. Microwave
  3. Infrared
  4. Visible Light
  5. Ultraviolet
  6. X-Ray
  7. Gamma Ray
• Frequencies is called?


  Electromagnetic Spectrum
• As the wavelength increases?

  The frequency decreases
• This is the ones that human sees, a small part of the spectrum.

  Visible light
• Used to transmit data and have been used in various application like: radio, satellites, radar and computer networks.

  Radio waves
• (Radio waves in medicine)

  • used to produce image of soft tissues, fluid, fat and bone(ecx. MRI and RFA)
  • Diagnose problems(ex. tumors)
• What is the meaning of MRI?

  Magnetic Resonance Imaging
• What does RFA means?

  Radio Frequency Ablation
• Uses heat to destroy cancer cells


  Radio Frequency Ablation
• Useful in communication because they PENETRATE clouds, smoke and light rain.


  Microwaves
• Used in Radar to predict the weather

  Microwaves
• Microwave in medicine

  • hyperthermia
  • Microwave ablation
  • Microwave diathermy
  • Transurethral Microwave
• Sometimes considered as "near" or "far" Infrared


  Infrared
• This is located between microwaves and visible lightin

  Infrared
• can be detected by heat and used in heat lamp

  Infrared
• Used daily in remote controls to read CD-Roms

  Infrared
• (Infrared in Medicine)

  • oncology
  • Vascular disorder
  • Respiratory disorder
  • Skeletal
  • Neuromuscular Diseases
  • Surgery
  • Tissue viability
• Portion of the EM spectrum that human eyes can detect

  Visible Light
• Different wavelength as colors in Visible Light

  • Blue has the shortest
  • Red has the longest wavelength
  • Light looks white if all colors are presented
• Used in tanning beds and sterilizing equipments

  Ultraviolet waves
• Ultraviolet in medicine

  • Has enough energy to enter skin cells
  • Shorter wavelength - UVB ray
  • longer wavelength - UVA
  • Used in treatment of Psoriasis and virtiligo
• Can UVA and UVB ray cause skin cancer?


  yes
• Can UV radiation be useful?

  • helps body to make vit. D for healthy bones and teeth
  • used to sterilized medical supplies and equipment
  • Detective uses fluorescent powder that helps to absorb UV and make it glow to find finger prints
• Too much exposure to X-Ray can damage living tissues and causes skin cancer
• come from radioactive elements or starts and has the highest frequency

  Gamma ray