Properties of waves 2

• What should you be able to describe by the end of this video?

  Changes in atoms with electromagnetic radiation
• 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 in atoms?

  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
• 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 a potential risk of 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 a 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?

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

  An alternating current
• What frequency does the alternating current have when created by radio waves?

  The same frequency as the radio waves
• What are the hazards of electromagnetic radiation?

  • Ultraviolet waves increase skin cancer risk
  • X-rays and gamma rays are ionizing radiation
  • They can cause gene mutations and cancer
• What are the key points about electromagnetic waves generation and absorption?

  • Changes occur in atoms or nuclei
  • Electrons can move to higher energy levels
  • Waves can be emitted over a wide frequency range
• What is the relationship between radiation dose and its effects?

  • Damage depends on radiation type
  • Damage depends on radiation dose
  • Dose measured in sieverts or millisieverts