Changes
What two types of changes can matter experience?
Chemical and physical changes
What are the two types of materials?
Natural and artificial
What type of energy do scissors use?
Human force
What happens during chemical changes?
The appearance and composition of matter change
What are natural materials?
They come directly from nature, we don't transform them
What are complex machines?
Machines that have many parts
What kind of change is combustion and oxidation?
A chemical change
What are artificial materials?
We produce them by transforming natural materials
What are simple machines?Machines that do not have many parts
Machines that do not have many parts
What happens during physical changes?
The appearance of matter changes but its composition doesn't change
What is elasticity?
When we stretch the material and it returns to its normal shape.
What are the four types of energy?
Human force, electricity, fuel and solar energy
When do changes of state happen and what are they?
They happen when we heat or cool matter. Solid to liquid, liquid to gas
What are the 4 properties of materials?
Hardness, elasticity, conductivity and buoyancy
What type of energy do planes use?
Fuel