Do Now Happy Valentine’s Day! Physical ScienceFebruary 14 th 2011 SWBAT identify the properties of solids liquids and gases. COPY THE FOLLOWING DEFINITION & EXPLAINATION The Kinetic Molecular Theory explains the forces between molecules and the energy that they possess. This theory has 3 basic assumptions: Matter is composed of small particles (molecules). The measure of space that the molecules take up (volume) is measured by the space in-between the molecules and not the space the molecules contain themselves. The molecules are in constant motion. This motion is different for the 3 states of matter.

Solids Liquids Gases Plasma

Have a definite shape Have a definite volume Molecules are held close together and there is very little movement between them. Kinetic Molecular Theory

Have an indefinite shape Have a definite volume Kinetic Molecular Theory Atoms and molecules have more space between them than a solid does, but less than a gas (ie. It is more “fluid”.)

Have an indefinite shape Have an indefinite volume Kinetic Molecular Theory Molecules are moving in random patterns with varying amounts of distance between the particles.

At 100°C, water becomes water vapor, a gas. Molecules can move randomly over large distances. Below 0°C, water solidifies to become ice. In the solid state, water molecules are held together in a rigid structure. Between 0°C and 100 °C, water is a liquid. In the liquid state, water molecules are close together, but can move about freely.

Changing states requires energy in either the form of heat. Changing states may also be due to the change in pressure in a system. Heat of formation, H f. Heat of vaporization, H v

Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible.

Plasma temperatures and densities range from relatively cool and tenuous (like aurora) to very hot and dense (like the central core of a star). Ordinary solids, liquids, and gases are both electrically neutral and too cool or dense to be in a plasma state.

(Above) X-ray view of Sun from Yohkoh, ISAS and NASAISASNASA Star formation in the Eagle Nebula Space Telescope Science Institute, NASA Space Telescope Science InstituteNASA (below)

Classwork & Homework Complete the Directed Reading: Classifying Matter – Must be turned in by end of class today Homework: Chapter 2 Section 1 – Pages 38  44 – Copy all definitions from section – Copy the summary on page 44