lesson 10 Flashcards
(24 cards)
What is nuclear fusion?
The joining of hydrogen atoms
This process forms helium atoms and releases a lot of energy.
How does hydrogen nuclei contribute to energy release?
They join together to form helium atoms
This process releases a significant amount of energy.
What is radiant light?
When light radiates (spreads out)
This concept relates to how light disperses in different environments.
What is the speed of light?
186,000 miles per second
Nothing travels faster than light.
What is incandescent light?
When you run electricity through a filament
This type of light is produced by heating a material until it glows.
Define filament.
A fragile thread-like strand
Filaments are commonly used in light bulbs.
What is the best metal used to conduct electricity?
Tungsten
Tungsten is preferred due to its high melting point and durability.
What does a light-emitting diode (LED) do?
Glows when electricity passes through it
Unlike regular bulbs, it directly creates light without heating a wire.
What does opaque mean?
When light can’t travel through an object
Opaque objects block light completely.
What do transparent and translucent mean?
When light can travel through an object
Transparent allows full light passage, while translucent allows partial light passage.
What is a shadow?
When an opaque object blocks light
Shadows are formed in areas where light is obstructed.
Define electromagnetic energy.
Energy that travels in waves, like light, radio signals, and X-rays
It moves through space using electric and magnetic forces.
What is the colour spectrum?
All the colours in the world
This includes both visible and invisible colours.
What is the visible spectrum?
The colours you see
This includes the range of light visible to the human eye.
What is the invisible spectrum?
The colours you can’t see
This includes ultraviolet and infrared light.
What is a prism?
Bends (or refracts) light and can split white light into a rainbow of colours
Prisms are often made of glass or other transparent materials.
What is ultraviolet light?
Light we can’t see with the naked eye because the frequency is too high
It is responsible for causing sunburns.
What is infrared light?
Has shorter wavelengths and generates heat
Infrared is used in various technologies, including remote controls.
Why does the sky look blue?
Sunlight hits the air and gets scattered
Blue light scatters more than other colours because it travels in shorter waves.
What are the two sets of primary colours?
Light: red, green, blue; Paint: cyan, magenta, yellow
These sets are used in different mediums for colour mixing.
What does reflective mean in terms of light?
Property of light that makes it bounce off things
Reflective surfaces include mirrors and calm water.
What does the angle of incidence refer to?
The law of reflection states that the angle of incidence equals the angle of reflection
This principle is fundamental in optics.
Define refraction.
The bending of light
Refraction occurs when light passes into a different medium.
When does light bend?
When it enters a different medium
This bending can change the direction of light rays.
