science unit 3, topic 1-3 wrap up Flashcards
(34 cards)
Bioluminescence
the emission of light produced by chemical reactions inside the bodies of living creatures
Chemiluminescence
the emission of light resulting from chemical action and not involving heat
Diffusion:
The movement of particles in liquids and gasses from an area of higher concentration to an area of lower concentration.
Fluorescence
the process in which high-energy, invisible ultraviolet light is absorbed by the particles of an object, which then emits some of this energy as visible light, causing the object to glow
Incandescence
The emission of visible light by a hot object
Phosphorescence
the persistent emission of light following exposure to and removal of a source of radiation
Opaque
Not allowing any light to pass through
Reflection
the casting back of light from a surface
Refraction
The bending of light when it travels from one medium to another.
Scattering
A small dispersed amount of something
Translucent
allowing some light to pass through. The light, however, is scattered from its straight path
Transparent
allowing light to pass through
What units do we use for electrical energy
- Kilowatt ( kW ) / watts (W)
What is the glowing portion of an incandescent bulb
Filament - the filament in the incandescent light bulb is heated by electricity, glows white hot and then changed to visible light energy
Parts of a fluorescent bulb
- Pin, lead-in wire, electrode, mercury, phosphor coating, tube, pin
how fluorescent light tubes make visible light energy
Electrical energy turns into Energy absorbed by mercury particles turns into energy absorbed by phosphor particles turns into Visible light energy.
Light energy given off by light/glow sticks
The light energy given off by glow sticks is called chemiluminescence or the glow stick is called a chemiluminescent light source. The breakable barrier in a glow stick separates two liquids that, when they touch, will cause a chemical reaction and glow/release light
Ray of light that hits a surface
Light rays will do a few things when they hit different surfaces:
Light rays will reflect off surfaces that it cannot pass through or surfaces that are more reflective
Light rays will be absorbed by dark opaque surfaces
Light rays can pass through transparent and a few translucent surfaces
Light rays can be scattered after they pass through a translucent surface
Light rays will refract or change direction/speed when passing through a different less or more dense medium
How does a 60 Watt and 100 Watt bulb differ
A 100 watt bulb would require more energy and electricity and has more power while a 60 watt light bulb would require less energy and electricity and has less power
Why do objects look bent in water
- Refraction causes the light to bend while traveling into different mediums. Light bends because it changes speed when it moves between materials that have different densities. The benign of light makes the object’s image appear in a different position from where the object really is.
Why can we see images in a mirror but not in a ceiling or wall
The walls will sometimes absorb light or scatter it randomly because they are usually rough surfaces, but mirrors reflect light easily and are commonly straight which is better for reflection.
How do we know light travels in straight lines
Because opaque objects cause shadows, which is only caused by light travelling in a straight line and that’s how we can tell light travels in a straight line
2 laws of reflection
the angle of reflection always equal to the angle of incident and vice versa
the normal line, the incident ray and the reflection ray lie in the same plane
Advantages and disadvantages of using incandescent and fluorescent light bulbs
Incandescent lights aren’t poisonous like fluorescent lights( they have mercury in them) Incandescent also costs less to manufacture but cost more to run
Fluorescent lights cost less to run, and are more energy efficient but cost more to make
