1 Label each of the particle diagrams below

1. Label each of the particle diagrams below with the state of matter each picture represents 1 2. 2 3 What are the differences between an atom, an element and a compound?

Discussion • Atoms closely packed together • A little space between atoms • very little movement • Atoms flow over each other SOLID LIQUID • A lot of space between atoms • Atoms move quickly GAS

Do Now Discussion What is the difference between an atom, an element and a compound? An atom is the smallest piece of matter. An element is one type of atom A compound is made of more than one element bound together

Chapter 12. 1: Gases and Kinetic Molecular Theory 3/30/11 Notes

Kinetic Molecular Theory (KMT) n What does it mean? ¨ Kinetic = to move ¨ Molecular = molecules/atoms ¨ It means Moving molecules! solid liquid gas

Why is KMT important? n Kinetic-molecular theory explains the different properties of solids, liquids, and gases (states of matter) n describes the behavior of matter in terms of particles in motion.

KMT Postulates (Rules) n n Gases consist of small particles separated by empty space. Gas particles are too far apart to experience significant attractive or repulsive forces. Gas particles move in straight lines until they collide with something else Kinetic energy of a particle depends on mass (m) and velocity (v) KE = ½mv 2

Kinetic Energy, mass and velocity m are KE, mvand v How related? v KE

Why are gases important? n n n Methane gas – an inexpensive fuel that we use to heat our homes and power our kitchen stoves Nitrogen gas – generated to inflate air bags in a car accident 2 Na. N 3 2 Na + 3 N 2 Oxygen – So we can breathe/live…kind of important.

Properties of Gases n There is a lot of “free” space between particles in a gas. n Gases can be compressed (reduce the space between particles) compression

Gases can be expanded infinitely (increase the space between particles) n Gases fill containers uniformly and completely. n

n Gases diffuse and mix rapidly. n Diffusion: the movement of one material through another ¨Example: food coloring in water ¨Gas Example: air freshener

Assignment Choose any three bullet points on your notes, copy them onto the back of your paper, then draw pictures showing what they mean