science unit 3, topic 1-3 wrap up Flashcards
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
Be able to draw a diagram labelled with the angles of incidence and reflection
reflecting surface, normal line, incident ray, reflected ray, angle of incidence, angle of reflection, the i and r and the angle degree, the arrows
Draw the path of light as it travels down through water
incident ray, water, refraction ray which bends toward the normal line, then the next incident ray, then the refracted ray that bends away from the second normal line. the angle of incidence outside the water is equal to the angle of refraction outside the water on the other side.
Know the cost of electricity (equation and solve)
Convert watts into kilowatts by dividing the watts by 1000 (kW).
Then times your kilowatts by the hours to get kilowatt hours (kWh).
Then times your kilowatt hours by the amount of cents per kWh to get your cost.
why does light seem to change and bend in the water
it refracts because the light ray changes directions as it travels through a different medium
light
the form of energy that we can see
what is the basic principle of light
Light can be absorbed by many surfaces and can be changed into several different forms of energy.
What are the 3 ways light can be transformed and The change from electrical energy to visible light energy involves what energy transformation
thermal energy, chemical energy, and electrical energy
thermal energy
what are the five main sources of light and examples of each - also how they get visible light energy
incandescent light sources - turn electrical energy into thermal energy, which turns into visible light energy - incandescent light bulbs, flood lights, and neon lamps
fluorescent light sources - turn ultraviolet light energy into energy absorbed by particles, that turn into visible light energy - fluorescent light tubes, LEDs, and xenon arc-lamps
Phosphorescent light sources - there is a delay before the phosphorescence releases visible light. - glow in the dark toys and behind TV screens
chemiluminescent light sources - turns chemical energy into visible light energy. - glow sticks and fireworks
bioluminescent light sources - causes living creatures to grow - deep sea fish, fireflies and some algae
Summarize in your own words the Ray Model of Light
light travels in straight rays that can bounce off of objects or go through clear objects, and it doesn’t curve.
What are the 2 types of mirrors and give an example of how they’re used
concave mirrors are mirrors that are curved inward and are used to focus an image onto a screen or can create a real image.
convex mirrors are mirrors curved outward and have a larger field of view to see larger areas.
