1. Describe the movement of the particles in the air. 2. Choose two different particles found in the air. Explain how they are different and how they are the same.

3. Describe air using the terms: mixture, atoms, and molecules.

4. What is one source of CO2 ?

5. Describe the relationship between atoms and molecules.

6. Is the composition of air consistent? Explain your thinking.

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost