1. Chapter 13

2. Maxwell 1831-1879 Boltzmann 1844-1906

3. Amadeo Avogadro (1776-1856)

4. 1818-1889

5. Equations

6. Revision Task  Use the paper in front of you  Summarize everything you can remember about Gases from before summer  For example: Equations, definitions, scientists etc…

16. Hints for 90S 1.A histogram is a bar chart where the area of a particular bar is related to the total number in that range. As the range intervals are the same here this is not a problem. 2.Which is most common? 3.Work out the average of (100 + 100 + 100 + 100 + 100 + 150 + 150 + 150 + 150 + 150 + 150 + 150 + … + 600 + 600 + 600) / 150. This method is tedious and error-prone. Is there a quicker way? 4.Square each speed, multiply by the number of molecules with that speed, add all 11 categories up and divide by the total number of molecules. Don’t forget to take the square root of the total at the end. 10.The ideal equation is: Density = mass / volume so eliminate the volume term. 13.You should show that the faster hydrogen and helium molecules travel at speeds comparable with the escape speed. What happens to these faster molecules? What happens to the slower ones that remain?