Water, Wind, chemicals and people tearing up the land are the major causes of this.
What is soil erosion?
100
This large satellite orbits our planet every 28 - 29 days.
What is the moon?
100
This special wheel with a rope wrapped around it is often seen in blinds so when you pull down, they go up.
What is a pulley?
100
This is what happens to water when you leave a pot of it over a campfire.
What is evaporation?
100
When the weather gets colder, some animals dig burrows to live in the ground. They do this without being taught.
What is instinct?
200
This precious resource can be conserved by being careful when we brush our teeth or take a shower.
What is water?
200
This is the time it takes for our planet to revolve around the sun?
What is 365 1/4 days?
200
This simple machine is wide at one end but pointed at the other. It can be used to split things apart.
What is a wedge?
200
This is the water we often see on the outside of a cold drink can or a hot, steamy mirror.
What is condensation?
200
Some types of moths have large eye spots on their wings. Thse spots look like the eyes of a much larger animal which scares away animals that might want to eat the moth.
What is mimicry?
300
These 3 layers make up the soil.
What is topsoil, subsoil and bedrock?
300
In order for the Earth to have night and day, it must do this!
What is rotate?
300
If we combine more than one simple machine, like in a bicycle, wheelbarrow or scissors, then you would have one of these.
What is a compound machine?
300
This is what it takes to turn a liquid into a gas.
What is heat?
300
Organisms, such as grss, that use the sun's energy to make food are called these.
What are producers?
400
This process of wearing down rock over a long period of time will eventually result in making soil, even though it takes about 500 years!
What is weathering?
400
If it wasn't for this, we would have the same season all year round, like at the equator!
What is the tilt of the Earth's axis?
400
This simple machine uses a stiff bar that moves on a fixed point. It works well to lift heavy things or pop the lid off of a paint can.
What is a lever?
400
This is the kind of precipitation you would see on a day in July in Virginia.
What is rain?
400
These plants rarely or never loose their leaves because they usually have needles and cones, that is why they are "ever green."
What are coniferous trees?
500
This resource is most important for all life on earth because it provides support, nutrients and water for plants to grow.
What is soil?
500
Sometimes called the "half moon", we actually are seeing only one fourth of the moon (if you counted the far side)!
What is quarter moon?
500
This simple machine is actually an inclined plane wrapped around a cylinder.
What is a screw?
500
Oh, no! Mrs. Frisinger just dropped a glass. This is the only thing that changed.
What is the size and shape of the glass?
500
Organisms, such as mushrooms or earthworms, that break down dead plants and animals into smaller pieces that can be used again by other living things are called this.