Grade 4 Light Flashcards
What is light?
Energy that is visible to the human eye.
What is a wave?
A vibration that moves energy from one place to another.
Explain reflect.
The action of light bouncing off of an object like a mirror.
Explain absorb.
When light changes to heat when entering an object, light a black shirt.
What does transparent mean?
A word that describes an object that allows light pass through it.
Give an example of something that is transparent.
Clear glass, plastic wrap.
What does opaque mean?
A word that describes anything that blocks light energy and does not allow light pass through it.
Give an example of something opaque .
A piece of wood, metal
Explain translucent.
A word that describes things which only partially block light, allowing some of it pass through.
What is an example of something translucent?
sheer curtains, paper
What is a shadow?
A dark area caused when light is blocked by an object.
What is an optical illusion?
When things look different to us then they really are- like a broken pencil in a glass of water.
What is a lens?
A special piece of glass or other transparent material that are shaped to bend or focus light, changing the way they look.
What is a prism?
A special piece of glass that separates white light into all the colors of the rainbow.
What is the acronym for the colors of the rainbow in the order of their appearance in the color spectrum? What does each letter stand for?
ROY G BIV - Red, Orange, yellow, Green, blue, indigo and Violet.
What are the 2 types of light sources?
natural and artificial.
What are some examples of natural light?
fireflies, fire, sun, lightning.
What are some examples of artificial light?
flashlights, fireworks, light bulbs.
What is natural light?
light sources that are not made by humans.
What is artificial light?
light sources made by humans.
What othe energy do light sources usually give off?
heat.
What kind of lines does light travel in? What are these lines called?
straight lines called rays.
Can light travel around corners?
no
When an object is placed closely in front of a light source, what size is its shadow? Why?
larger, because it blocks a lot of light.
When an object is placed far away from a light source, what size is it’s shadow? Why?
smaller, because it blocks less rays of light.
To make an evenly dark shadow, should you have a large or small light source?
small
A shadow with fuzzy edges occurs when?
When the object is farther from where the shadow falls.
A shadow with sharp edges occurs when?
When the ogject is close to where the shadow falls, such as on a wall.
The middle, darker part of a shadow is called what?
umbra
The lighter outside edges of a shadow is called what?
penumbra
What is meant by luminous?
luminous is radiating or reflecting light.
What is meant by illuminated?
Illuminated is to supply or brighten with light.
What is the clear, tough outer coating that protects the eye called?
The cornea
What is the colored part of the eye that controls the opening and closing of the pupil called?
The iris.
What controls the amount of light that enters the eye by opening and closing called?
The pupil.
What is the part of the eye that focuses the light that enters the eye called?
The lens
What forms the back wall of the eye?
The retina
What carries the message from the retina to the brain?
The optic nerve.
Please label this eye:
