Wave Properties

• Waves and radioactive radiation are topics for revision

Waves

• A wave is a disturbance in a medium

• Waves carry energy without net movement of particles

• Two types to know:

  • Transverse
  • Longitudinal

• Frequency

  • How many whole waves pass a fixed point in a second

• Hertz is the measure of frequency

  • Hz,

• Wave speed is measured in meters per second

  • m/s

• Wavelength is measure in meters

  • m

• v = fλ

Electromagnetic Waves

• Includes radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays
• Radio waves:
  • Broadcast radio and television
• Microwaves:
  • Used in cooking, radar, and telephone signals
• Infrared:
  • Transmits heat from the sun, fires, and radiators
• Visible light:
  • Makes it possible to see things
• Ultraviolet
  • Absorbed by the skin
  • Used in fluorescent tubes
• X-rays:
  • Used to view inside of bodies and objects
• Gamma rays:
  • Used in medicine for killing cancer cells

Electromagnetic Spectrum

• Includes non-ionizing radiation (radio waves, micro waves, infra red, visible light)
• Includes ionizing radiation (ultra violet, X-ray, gamma rays, particle radiation)
• Particle radiation occurs with alpha and beta particles

Medical Uses of Rays

• Gamma ray for Nuclear medicine PET imaging
• Ultraviolet for analyte determination
• Infrared is a radiation
• Radiowaves is a radiation
• X-rays are for bones and soft tissue
• Microwaves are used in ultrasounds

Dangers of Waves

• Radio:
  • Has no known danger
• Microwave:
  • Possible heat damage to internal organs
• Infrared:
  • Skin burns
• Visible Light:
  • Bright light can cause eye damage
• Ultraviolet:
  • Eye damage
  • Sunburn
  • Skin cancer
• X-rays:
  • Kills cells
  • Mutations
  • Cancer
• Gamma Rays:
  • Kills cells
  • Mutations
  • Cancer

Standing Waves

• Standing waves, or stationary waves, are a wave-like swing motion that forms a pattern of fixed knots
• The wave is in a constant position
• Two opposite-facing waves form a standing wave

Bending Waves

• Waves tend to bend off behind an islet, a pier or the like in water
• Sound waves bend around edges and fill the entire room, making them audible around corners

Interference

• Interference emerges when two or more waves appear in a point
• It creates a new wave that will in general have new properties such as altered frequency or amplitude.

Wifi

• Mobile phones use microwaves
• Phones are essentially two-way radios
  • They transmit and receive signals
• Phones use two wavelengths at once
  • One sends and one receives

Telescopes

• Telescopes are used for wave emission from elements
• Emissions are unique for each element
• Each element is used to identify what it is made up of

Red Shift & Blue Shift

• Used to measure distances, and direction of Galaxies
• Includes moving toward you: blueshift (compression)
• Includes moving away from you: redshift (expansion)

Radioactive Radiation

• Used for medical treatment
• Nuclear medicine uses radiation for diagnostics and treatment
• Techniques use radiation and radioactive isotopes
• One in every two people will benefit from nuclear medicine during their life

Radon

• Radon is an invisible and odorless radioactive gas
• Radon levels above 100 Bq/m³ require measures to reduce the level
• Radon level should not exceed the limit value of 200 Bq/m3
• Radon in indoor air increases the risk of lung cancer

Fission and Fusion

• Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei
• Fusion is the process where two light nuclei combine together releasing vast amounts of energy

Greenhouse Effect

• Includes Natural Greenhouse effect and the Human Enhanced Greenhouse Effect
• Natural sources of climate forcing include the sun and the atmosphere
• Human sources of climate forcing include CO2 and CH4

Ozone Layer

• Lies within the Earth's stratosphere
• Ozone Layer Depletion from chlorofluorocarbons
• The Ozone layer protect from UV radiation

UVA, UVB and UVC Radiations

• Protection can be achieved using sunglasses, sunscreen hats, and protective clothing

Positive Effects of the Sun

• The sun produces Vitamin D in humans

Ionizing Radation

• Ionization is the ability for a force to eject a bound electron from an atom or molecule
• Includes alpha, beta, and gamma radiation

Radiation

• Alpha Radiation
  • Composed to 2 protons and 2 neutrons
  • Charge is +2
• Beta Radiation
  • Composition is Electron
  • Charge is -1
• Gamma Radiation
  • Composition is high energy electromagnetic radiations
  • Charge is 0

Geiger Counter

• Geiger counters are used how radiation is detected

Test your knowledge of wave properties including frequency, wavelength, wave types (sound and electromagnetic), interference, diffraction, and refraction. Explore wave behavior and related natural phenomena. Assess wave characteristics with this quiz.