Electromagnetic Waves
True or False? Electromagnetic waves require a medium (matter) to travel.
False - EM waves can travel through empty space as well as through matter.
These waves are just beyond visible light. They come from the sun ands can cause sunburn and damage to the skin, but they also help produce Vitamin D.
ultraviolet (UV)
Curtains blocking sunlight from entering a room.
absorption
The air in an empty room. Light travels straight through it, allowing you to see the walls, furniture, and people across the room with perfect clarity.
transparent
Digital, analog, or both? Generated in nature and distorted easily in transmission.
analog
True or false? Humans can see all forms of waves on the electromagnetic spectrum.
False - Humans can only see visible light waves.
The highest-energy waves with the shortest wavelength. They are produced by radioactive materials and cosmic events. They penetrate most materials and are used in medical treatments but can be harmful to living tissues.
Gamma rays
Seeing fish through clean water.
transmission
Fog is a thick cloud of tiny water droplets resting right at ground level. It acts like a giant, blurry screen that lets light pass through but scatters it so you cannot see clear details.
translucent
Digital, analog, or both? Patterns of the waves determine the info carried by the signal.
both
In light waves, amplitude determines _______.
In sound waves, amplitude determines ____.
brightness, volume
These waves are mostly felt as heat. Remote controls and night-vision goggles use these waves.
infrared
Headlights shining back from a road sign at night.
reflection
A solid wooden door. When the door is closed, it completely blocks the light from the hallway. You cannot see any shapes, colors, or movement on the other side because no light can pass through it.
opaque
Digital, analog, or both? Continuous wave with infinite values and changes in frequency, amplitude and wavelength code for information.
analog
In light waves, frequency determines _______.
In sound waves, frequency determines ____.
color, pitch
High-energy waves used in medicine and security to view inside objects (like bones or luggage). They can also be harmful if overexposed.
X-rays
Moonlight coming off the surface of the Moon.
reflection
If you hold a piece of wax paper up to a light, the glow shines right through it. However, if you try to read a book through the paper, the letters look like blurry, fuzzy shapes that you cannot fully see.
translucent
Digital, analog, or both? More reliable transfer from original to copy and square wave with only two values.
digital
Out of all the electromagnetic waves, radio waves have the:
________ wavelength
________ frequency
________ energy
longest wavelength
lowest frequency
lowest energy
These waves are in radar systems and in communication. They are also absorbed by water, which makes them useful for heating food.
microwaves
When we look at a red apple, the color red is ____________ and all other colors are _________.
reflected, absorbed
If you stack five sheets of translucent tissue paper together, they will likely become this property instead.
opaque
Digital, analog, or both? Can be transmitted across long distances.
both