Unit 3 Review Science Test Flashcards
Definitions!
Electromagnetic Radiation
A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
Definitions!
Ray Model Of Light
A model that represents light as a stream of fast-moving tiny particles that travel in a straight line to the eye where they are absorbed to form an image.
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Wave Model Of Light
The wave model of light pictures lights traveling as a wave.
Definitions!
Particle Model Of Light
Light consisted of particles that traveled in straight lines.
Definitions!
Wavelength
Wavelength is the distance between identical points like trough to trough or crest to crest
Definitions!
Frequency!
The number of waves that pass a fixed point in unit time
Definitions!
Amplitude
the maximum displacement or distance moved by a point or the distance between the crest and center line
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Reflection
The return of light or sound waves from a surface
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Absorption
The transfer of the energy of a wave to matter as the wave passes through it.
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Transmission
Transmission of light is the moving of electromagnetic waves whether visible light, radio waves, ultra violet etc. through a material.
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Refraction
The changes in the direction of a wave passing from one medium to another are caused by its change in speed.
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Laws Of Reflection
When a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
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Plane Mirror
A mirror with a flat reflective surface.
Definitions!
Concave Mirror
Has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point.
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Convex Mirror
A mirror in which the reflective surface bulges toward the light source and reflects the light outwards
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Lens
A piece of glass or other transparent substance is used to form an image of an object by focusing rays of light from the object.
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Converging Lens
A lens that causes parallel rays (as of light) to come to a focus.
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Diverging Lens
A lens that causes a beam of parallel rays to diverge after refraction, as from a virtual image
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Far Sighted
A condition in which you can see distant objects clearly, but objects nearby may be blurry. It’s a result of the visual image being focused behind the retina rather than directly on it. You can use prescription lenses to fix it.
Definitions!
Near Sighted
A condition in which you can see nearby objects clearly, but distant objects may be blurry. It’s a result of the visual image being focused in front of the retina rather than directly on it. You can use prescription lenses to fix it.
Definitions!
Snow Blindness
Temporary eye pain and discomfort after exposure to too much ultraviolet (UV) reflected from snow or ice. Can be avoided if you wear goggles with thin slits.
Definitions!
Astigmatism
Imperfection in the curvature of the eye causes blurred distance and near vision. Occurs when either the front surface of the eye (cornea) or the lens inside the eye has mismatched curves. Can be fixed by laser eye surgery.
Definitions!
Laser Eye Surgery
A medical procedure that involves the use of a laser to reshape the surface of the eye.
Definitions!
Reflecting Telescope
A telescope that uses a single or a combination of curved mirrors that reflect light and form an image.
How does electromagnetic radiation shape your world?
- Electromagnetic radiation is an important part of your world.
- Sources of electromagnetic radiation are all around you.
- Electromagnetic radiation enhances how we sense our world.
How can models explain the properties of electromagnetic radiation?
- Visible light can be used to model all types of electromagnetic
radiation. - The ray model of light explains that light travels in straight lines.
- The wave model of light explains that light has wave-like properties.
- The particle model of light explains that light has particle-like
properties.
How does light behave when it encounters different materials and surfaces?
- Light can be reflected, absorbed, transmitted, or refracted.
- Light behaves differently when it encounters transparent, translucent,
and opaque materials.
How does light behave when it is reflected?
- Light is reflected in predictable patterns.
- Light reflected by a plane mirror produces an image that is nearly
identical to the object. - Light reflected by curved mirrors behaves in unique ways.
- Many technologies take advantage of light behavior when it strikes a
reflective surface.
How does light behave when it moves from one medium to another?
- Light changes direction and speed when it moves from one medium to
another. - Light refracts as it passes through lenses.
- Refraction plays a role in human vision.
- Many technologies take advantage of light’s behavior when it moves
from one medium to another.
Human Vision!
Light Enters the eye through the ____!
Pupil
Human Vision!
The _____ surrounds the pupil and controls the amount of _____ entering the eye…….._______ in dim light………._________ in bright light.
Iris, light, expands, constricts
Human Vision!
The _______ is a ________ tissue which covers the iris and pupil and does most of the ________.
Cornea, transparent, focussing
Human Vision!
The _______ is a white tissue around the iris.
sclera
Human Vision!
Light then passes through a _______ lens……image is formed of the back of the eye (______), which contains light receptor cells
Convex, Retina
Human Vision!
A signal is sent to the ______ along the _______ ______.
Brain, Optic Nerve
Human Vision!
The image formed on the retina is _______ _______, but the brain interprets it to be _______.
Upside Down, Upright
The ________ is a small spot on the retina where the optic nerve is…..there are no light receptors there.
Blindspot
Human Vision!
2 types of light receptors cells are ______ that allow us to see colors
and ________ that allow us to see in dim light
Cones, Rods
What is the Pupil!
The opening in the center of the iris!
What is the Blind Spot!
A place at the back of the eye on the retina which has few light-sensitive cells!
What is the Cornea!
The tough, clear, covering over the front of the eye!
What is the Iris!
The colored part of the eye!
What is the Lens!
The clear disk which focuses light rays into a sharp image.
What is the Optic Nerve!
The nerve that carries information from the eye to the brain!
What is the Retina!
The lining of the eye which contains millions of light-sensitive cells called rods and cones!
