34 terms

# Grade 5 Unit 2: Energy

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energy
The ability to do work.
potential energy
Stored energy.
kinetic energy
The energy of motion.
solar energy
Energy that comes from the sun.
Energy that travels to the earth in the form of waves, also known as solar energy. It lights and heats our earth to sustain life on earth. It affects the water cycle, wind cycle, our seasons, and other important processes, such as photosynthesis in plants.
electromagnetic
Made by sending an electric current through a wire wrapped around a metal object, such as a nail.
reflect
The bouncing of light off a surface, such as a mirror. A surface does not have to be light and shiny for light to bounce off of it.
absorb
Light that soaks into, such as a black chair sitting where the sun can shine on it.
refract
When light bends at the surface, such as a rainbow. When light rays bend, they slow down because they are traveling from one medium ( such as air) to another medium (such as water).
transmit
When light passes through objects, such as a window.
law of reflection
When light reflects off of (bounces off of) matter, the angle of incidence (the angle at which it hits the surface) is equal to the angle of reflection (the angle at which it bounces off a surface).
visible light
Light that we can see. These are the colors of the rainbow, red, orange, yellow, green, blue, indigo, and violet. These colors make up the sun's white light. It's wavelengths are short and long enough for us to see.
ultraviolet light
Light that we cannot see because it's wavelengths are too short.
law of refraction
Snell's law (also known as Descartes' law, the Snell-Descartes law, and the law of refraction) is a formula
used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass. The law says that the ratio of the sines of the angles of incidence and of refraction is a constant that depends on the media.
concave lens
A lens that is thinner in the middle than on the ends. The lens looks like the opening to a cave-it curves inward.
convex lens
A lens that is thicker in the middle than on the ends; it bulges outward. The lens is shaped so that the rays come together at a single point, the focal point.
transparent
When light is seen clearly through an object.
translucent
When light is blurry as it passes through an object.
opaque
When light cannot pass through an object.
conduction
When heat passes through a material while the material stays the same. It occurs by molecules bumping into each other and gaining energy. Molecules in a hot substance come into direct contact with cooler substances and heat is transferred. An example is heat traveling through a rod that is held over a lit candle.
convection
When heat travels from hot parts of a material and rise while cooler parts sink. An example is an electric furnace.
electrical energy
Energy that is the result of electrons moving freely in a complete or closed circuit. It must have an energy source, such as a battery.
circuit
A path that is made from an electrical current.
chemical energy
Energy released in chemical reactions. A form of potential energy and results from the making and breaking of chemical bonds. A battery stores this type of energy. In photosynthesis, plants convert radiant energy from the sun into this type of energy in the form of glucose or sugar. Our bodies store this type of energy from the foods we eat and convert it into heat and the energy of motion.
electron
Negatively charged particles of atoms.
system
All parts work together to perform a common goal.
photosynthesis
A chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight.
mechanical energy
Energy of objects in motion. Examples are a moving train, a runner, a mixer or blender, a roller coaster, a vending machine, a hamster exercising on a wheel and robots all have parts that move and are in motion.
transformation
Energy changing from one form to another.
closed/complete circuit
An electric circuit providing an uninterrupted, endless path for the flow of current.
open/incomplete circuit
An electrical circuit in which no current flows.
sound waves
An alternating area of high and low air pressure that transmits energy through a medium.
vibration
An oscillatory motion—a movement first in one direction and then back again in the opposite direction. It is exhibited, for example, by a swinging pendulum, by the prongs of a tuning fork that has been struck, or by the string of a musical instrument that has been plucked.
light energy
A form of energy that we can see.