P6: Waves

• What hazards are associated with ultraviolet, x-rays, and gamma rays?

  They can be hazardous to the human body
• What is emitted by lithium atoms when heated?

  Red light
• How are electromagnetic waves produced when atoms are heated?

  Electrons move to higher energy levels
• What happens when an electron returns to its original energy level?

  It generates an electromagnetic wave
• What type of radiation can be emitted from the nucleus of radioactive atoms?

  Gamma rays
• What happens to the energy of a nucleus after emitting a gamma ray?

  The nucleus has less energy than before
• What can happen when electromagnetic waves are absorbed by atoms?

  Electrons can change energy levels
• What is the frequency range of emitted and absorbed electromagnetic waves?

  From radio waves to gamma rays
• What is the risk associated with ultraviolet waves?

  Increased risk of skin cancer
• What type of radiation are x-rays and gamma rays classified as?

  Ionizing radiation
• What can x-rays and gamma rays cause when absorbed?

  Mutation of genes
• How is the dose of radiation measured?

  In sieverts or millisieverts
• Are students expected to remember the unit of radiation dose for exams?

  No, but they may interpret data
• How can radio waves be produced?

  When electrons oscillate in an electrical circuit
• What does the term "oscillate" mean in the context of radio waves?

  Move backwards and forwards
• What happens when radio waves are absorbed by an electrical circuit in an aerial?

  Electrons in the circuit oscillate
• What can the oscillation of electrons in a circuit create?

  An alternating current with the same frequency
• What should you be able to describe by the end of the video?

  Uses of electromagnetic waves
• What is required for higher tiered students in this lesson?

  Explain why each wave type is suitable
• What are some uses of electromagnetic waves mentioned in the video?

  • Radio waves for radio and TV signals
  • Microwaves for heating food and satellite communication
  • Infrared for heating and cooking
  • Visible light for fiber optic communication
  • Ultraviolet for energy-efficient lightbulbs and tanning
  • X-rays and gamma rays for medical imaging and treatments
• What are radio waves used for?

  Transmit radio and terrestrial TV signals
• Why are radio waves suitable for long-distance travel?

  They can travel long distances before absorption
• What is diffraction in relation to radio waves?

  Spreading out between hills
• What is the ionosphere's role with radio waves?

  Reflects radio waves for long-distance travel
• What is the primary use of microwaves?

  Heating food
• Why do microwaves heat food effectively?

  Water molecules absorb microwave energy
• How do microwaves communicate with satellites?

  They pass through Earth's atmosphere easily
• What is infrared used for?

  Heating and cooking food
• How does infrared energy affect room temperature?

  It is absorbed by objects, warming them
• What is a use of infrared cameras?

  Check buildings for heat losses
• What is a key use of visible light?

  Communication using fiber optics
• What are optical fibers made of?

  Thin strands of glass
• Why can visible light carry a lot of information?

  It has a short wavelength
• What is a significant use of ultraviolet light?

  Energy-efficient lightbulbs
• How does ultraviolet light create visible light in bulbs?

  It is absorbed and converted to visible light
• What is a risk associated with ultraviolet light?

  Increases skin cancer risk
• What are x-rays used for?

  Visualizing broken bones
• Why can x-rays visualize bones?

  They are absorbed by bones
• What is a use of gamma rays?

  Detecting cancers
• How are x-rays and gamma rays used in medical treatments?

  To treat cancer