1.2 Kinetic Molecular Theory Miss Martel

The Particle Model of Matter All matter is made of small particles There are spaces between the particles. The particles are always moving. The particles are attracted to each other. The particle model of matter describes ATOMS!

Kinetic Molecular Theory Scientists used Particle Model of Matter to develop KMT KMT is based on Kinetic energy Kinetic energy is the energy of motion All particles are always moving, so they have kinetic energy

Kinetic Molecular Theory Since particles are way to small for us to see we are going to use a simulation to see what is happening at the molecular level.

Kinetic Molecular Theory Hopefully the simulation helped you see what KMT is about Here are the main points of the KMT: All matter is made up of very small particles There is empty space between particles Particles are constantly moving. In liquids and gases, the particles are colliding with each other and the wall of their container Particles of a solid are so tightly packed together that they cannot move around freely. They can only vibrate Particles of a liquid are farther apart, and they can move by sliding past each other Particles of a gas are very far apart, and they move around quickly.

Kinetic Molecular Theory Here are the main points of the KMT: 4. Energy makes particles move. The more energy the particles have, the faster they can move and the farther apart they can get. There is more energy as temperature gets hotter. 5. Attraction between particles decreases as the distance between particles increases. With your partner fill in information on solids, liquids and gases on page 8 of your hand out

KMT and Changes of State Solid: Particles are tightly packed together Particles can only vibrate Attractive forces are high Increasing energy causes an increase in vibration Liquid: Particles are farther apart Particles still vibrate, but can move, sliding, or bumping past one another Attractive forces are quite high, but less than solids and decreasing with distance Increasing energy causes increase in vibration and movement

KMT and Changes of State Gas: Particles very far apart Particles vibrate, rotate, bump, and move past each other in rapid straight line motion No attractive forces; particles are too far apart and are moving too fast Increasing energy causes an increase in pressure Because the increase in speed & number of particles hitting the sides of the container

Temperature and Changes of State Changing from one state to another involves adding or removing energy What type of change is that? physical change What we experience as HEAT, the particles experience as MOTION.   1. Adding heat  particles move faster 2. Cooling down (removing heat)  particles slow down  

Temperature and Changes of State Fill in the chart on handout on page 9. During the changes of state is energy gained or lost?

Temperature and Changes of State Demo time! Remember everything that we have learnt so far about KMT try and visualize what is happening and try to be able to explain it!

Describing Matter What are properties? characteristics, or ways of describing matter they have to be observable or measurable there are two types of properties : Qualitative = Properties that can be described but not measured Quantitative = Properties that can be measured numerically Put the property words under qualitative or quantitative

Homework Reading Questions: # 1-7 Finish defining and putting properties under qualitative or quantitative

Describing Matter