Today’s special Turn in Practice test & Lab on front table Test 9 Thermal energy Turn in test and work on Vocab sheet quietly, without talking Vocab 10 due next Notes!

Heat transfer and phase change PAc.1: Distinguish chemical properties of matter (including reactivity) from physical properties of matter (including boiling point, freezing/melting point, density [with density calculations], solubility, viscosity, and conductivity). PAc.6:Compare the properties of the four states of matter—solid, liquid, gas, and plasma—in terms of the arrangement and movement of particles. PAc.7:Explain the processes of phase change in terms of temperature, heat transfer, and particle arrangement. PAa.2:Use appropriate laboratory apparatuses, technology, and techniques safely and accurately when conducting a scientific investigation. PAa.9:Use appropriate safety procedures when conducting investigations.

Write it on your heart that every day is the best day of the year. Ralph Waldo Emerson Fact: Every year, the moon moves ½ inch further from the earth.

Today’s special Homework check (Vocab 10) Test results Notes HW I due next Activity (Practice book)

Question Why does water in a car radiator sometimes boil explosively when the radiator cap is removed?

Conduction Transfer of heat by means of particles, mainly electrons Metals have freely moving electrons, and are generally good conductors

Insulators Substances with electrons that do not move freely Wood, air, rubber

Home insulation Has “R” rating according to climate

Today’s special Safety moment Notes Class work time

The best insulator Dead air space, i.e.: Double pane windows Polystyrene

Convection Heat transfer by motion of currents in fluids, liquid or gas

What is forced convection? The currents are helped along by adding a fan

Radiation (radiant energy, NOT radioactivity!) Transfer of heat energy by electromagnetic waves

radiant energy All substances above absolute zero absorb, emit, and reflect radiant energy

Phase change A change of state from solid, liquid, or gas

Today’s special HW check A few more notes Lab

Today’s special HW I check Upcoming schedule Chapter project & HW II Safety project & Take-home test Lab A few more notes

Evaporation Molecules absorb energy until they can break free of the liquid

condensation Molecules give up their energy to a liquid

Boiling and pressure Boiling points can be changed by increasing or decreasing pressure Increased pressure prevents molecules from leaving (pushing down on the “pile”) Decreased pressure helps molecules to leave (helping the football players up)

Pressure cooker

Melting and freezing Add energy, molecules move more and substance melts Take out energy, molecules slow down and arrange themselves into a solid Adding a “foreign” substance interferes with the crystal formation process

Melting ice

Question Why does water in a car radiator sometimes boil explosively when the radiator cap is removed?

Homework Chapter HW: pp I. Review questions2-20 even (due date: ____________) II. Exercises 2-20 even; Problems 1-7 (due date: __________)