What type of fossil fuel is found as a gas deep underground?
natural gas
What is the difference between renewable and nonrenewable resources?
Renewable resources come back someday after we use them.
What is recycling?
Recycling is when we make something new out of something old that we've already used before.
liquid -> solid
What is this state change called?
freezing
solid -> liquid
What is this state change called?
melting
What type of fossil fuel is found as a liquid deep underground?
oil
Soil is a natural resource. Why is it important that we conserve soil?
Soil provides food, shelter, and water for many organisms.
We need trees for respiration. What does that mean?
Respiration is when trees convert CO2 into O2 for us to breathe, then we convert O2 to CO2 for them to breathe.
What state of matter is this?
- cannot change shape
- cannot change volume
solid
gas -> liquid -> solid
Are these state changes because of heat lost or heat gained?
heat lost
What type of fossil fuel is found as a solid between rocks?
coal
______ is what we put in our cars. It's made out of oil.
petrol/gasoline
Tell me a good way to reduce the amount of paper we use at school.
We can do homework on koobits instead of on paper
... (many correct answers)
What state of matter is this?
- can flow
- cannot expand
liquid
liquid -> gas
What is this state change called?
boiling or evaporation
How are fossil fuels created?
Fossil fuels come from dead organisms that stay underground for millions of years.
Soil ______ the roots of plants. That means it holds them in place and helps them stand up.
anchors
If we pollute the oceans, rivers, and lakes, we will destroy many ______ environments.
aquatic
What can gases do that other states of matter cannot do?
They can flow/change shape and expand/change volume.
gas -> liquid
What is this state change called?
condensation
A ________ is a place where fossil fuels are processed for us to use them.
refinery
We can make ______ by mixing two metals together. These are often more useful than pure metals.
alloys
After we ______ resources from the ground, we cannot use them again.
extract
At 0°C, solid water becomes liquid water, but solid gold does not become liquid gold. Why not?
Gold has a higher melting point than water. It melts at 1064.2°C, while water melts at 0°C.
What is the difference between boiling and evaporation?
Boiling happens when a material reaches its boiling point. Evaporation can happen at any temperature.
For example, liquid water boils to steam at 100°C (boiling point). It can evaporate to water vapor at any temperature.