Ch. 9 Heat and States of Matter! Ch. 9 Sections 1-2

Temperature= measure of the average kinetic energy of its particles But what is kinetic energy? Kinetic energy= particles in matter are moving at different speeds in all directions; anything in motion has kinetic energy Temperature

Thermal energy= the sum of the kinetic and potential energies

The kinetic energy increases as molecules move faster The potential energy increases as the moleculs move farther apart Think about this…

Heat= thermal energy that flows from something at a higer temperature to something at a lower temperature *Heat always flows from a warm material to a cool mateiral Heat

Ice cream!

Example…how does ice cream become cold??? Thermal energy flows from warmer liquid ingredients to the cooler ice and salt mixture. The energy lost became cold enough to freeze and the ice and salt absorbed thermal energy causing some of the ice to melt. Example…how does ice cream become cold???

Ch. 9 Sec. 2: States of Matter Solid, Liquid, Gas, Plasma! Ch. 9 Sec. 2: States of Matter

Solids Particles are packed closely together and vibrate in place. Fixed volume and shape. Solids

Liquids Particles slide past each other Takes the shape of their container Partile forces are weaker than a solid but stronger than a gas Have definite voluem but no definite shape (since they take the shape of their container) Liquids

Gas Particles farther apart Attractive force are weak No definite shape or volume Gas

Plasma Matter consisting of positive and gatively charged particles No shape or volume Results from collisions between particles moving at high speeds Examples= stars, lightning bolt, neon and fluorescent tubes, auroras Plasma

Changing states of matter Matter can change from one state to another by melting, freezing, boiling, vaporizing, condensing, etc. For example, freezing is when a _________ goes to a _____________. Changing states of matter

Melting When a ________ goes to a _________. Ice water As temperature increases, particles move faster (since they’re getting farther apart). Energy (heat) is required for particles to slip out of the solid arrangment to a weaker, liquid arrangment. Melting

Boiling Only associated with liquids Boiling point= temperature at which the pressure of the vapor in the liquid is equal to the external pressure acting on its surface This is a kind of VAPORIZATION changing liquid to gas This is why if you leave water boiling too long, you will have no water left  Boiling