microwaves and infrared

• What are the second and third groups in the electromagnetic spectrum discussed in the video?

  Microwave radiation and infrared radiation
• How can microwaves be split into two different groups?

  • Microwaves not absorbed by water molecules: used for communication via satellites
  • Microwaves absorbed by water molecules: used in microwave ovens to heat food
• Why do microwaves have relatively long wavelengths and low frequencies?

  Because they are located on the far left of the electromagnetic spectrum
• Why are microwaves used for communication via satellites?

  They can pass through the Earth's atmosphere without being absorbed by water molecules
• How do microwaves help heat food in microwave ovens?

  The energy from microwaves is absorbed by water molecules, causing them to vibrate and transfer energy
• Why do foods with more water heat up more quickly in a microwave?

  Because they absorb more energy from the microwaves
• What is infrared radiation emitted from?

  All objects that have thermal energy or heat energy
• How does the amount of infrared radiation emitted by an object depend on its temperature?

  The hotter the object, the more infrared radiation it emits
• What is one use of infrared radiation in technology?

  Infrared cameras help us see in the dark and spot living organisms
• How do infrared cameras detect living organisms?

  By measuring the amount of infrared radiation emitted, indicating temperature differences
• Why do warm animals appear bright in infrared images?

  Because they emit lots of infrared radiation
• How does infrared radiation cook food differently than microwaves?

  Infrared radiation doesn't penetrate the surface of the food
• How does a toaster cook bread using infrared radiation?

  By heating metal to high temperatures, which emits infrared radiation
• How do electric heaters use infrared radiation?

  They heat up metal, which then emits infrared radiation to warm the surroundings
• When are microwaves and infrared waves harmful to us?

  In high quantities
• What happens to living cells in a microwave?

  They would boil and be destroyed
• What could happen if you put your hand too close to a grill?

  You would probably get burns as nearby skin cells would be destroyed
• What are the main uses of microwaves and infrared radiation?

  Microwaves:

  • Communication via satellites
  • Heating food in microwave ovens

  
  

  Infrared Radiation:

  • Night vision with infrared cameras
  • Cooking with ovens and grills
  • Heating rooms with electric heaters