Study Hall: Sharpen your pencils…. Find your seat…… Work on something quietly at your desk…

Written Response May 8

Our mission today is to… Review conductors and insulators (electrical and thermal) Review the Electromagnetic Spectrum

We will also review how certain materials contract and expand due to changes in heat Bridge

Add to your alphabet book Thermal energy is transferred through a material by the collisions of atoms within the material. It can warm objects.

Ice Melting Conductors/Insulators You will see ice cubes placed on 4 different surfaces: 1.Brick 2.Wood 3.Metal 4.Glass In your notebook: Predict: Out the 4 materials above….. which will melt the ice the fastest? which will melt the ice the slowest?

Let’s watch KBY KBY

Did you get it right???? I learned from the experiment that: The metal melted ice the ice fastest, therefore it is the best conductor of heat. The wood melted ice the slowest, therefore it is the best insulator of heat

Add to alphabet book….. Thermal conductors : materials that easily conduct heat Includes metals (aluminum, steel, and copper) they transfer heat and they hold heat easily too.

Examples of Thermal Conductors…

Think about cookware…. Most cookware is made from different types of metals because they are thermal conductors

Add to alphabet book Thermal insulators : materials that do not conduct heat Includes pot handles, spatulas, cooking utensils (do not get hot as easily) They reduce (limit) heat transfer

Think about cookware…. Notice the handles on the cookware….. The handles do not conduct heat because they are thermal insulators

Thermal insulators xc xc

Add to alphabet book Electrical conductor : materials through which an electrical current can flow easily Includes most metals

Examples of Electrical Conductors….

Add to alphabet book Electrical insulator : materials through which electrical current does not easily flow. Includes rubber, glass, porcelain, ceramic, plastics

Examples of Electrical Insulators….

Let’s predict… an electrical conductor or insulator? Copy chart in your notebook: “Our Conduction & Insulator Experiment” “ Object Hypothesis (Conductor/Insulator Result (Conductor/Insulator )

Add to alphabet book Expansion joint: joints that allow for expansion in hot weather and contraction in cold weather

Examples of Expansion and Contraction Joints… Bridge with expansion joints Sidewalk with expansion joints Road with no expansion joints….cracks over time with heating and cooling

Insulator/conductor?

Conduction, convection, radiation? Hot coffee is stirred with a spoon and the spoon gets hot

Conduction, convection, radiation? A chair is placed near a fireplace. The side of the chair closest to the fireplace gets warm

Conduction, convection, radiation? A lava lamp contains colored liquids. These liquids form globs that break off and rise to the top when the lamp is turned on.

Conduction, convection, radiation? A college student holds her hand near an iron to see if it is hot.

Conduction, convection, radiation? Warm air rises in a room.

Conduction, convection, radiation? You flip your pillow over and it feels cool on your face.

Add to alphabet book Temperature: measure of heat in an object Can change due to how intense a the light striking the surface is, how long the light shines on the object, how much of the light is absorbed.

Electromagnetic Spectrum

Remember Roxy May Is Victorious Using X-box and GameCube

Remember Wavelength is decreasing from LEFT to RIGHT (Radio to Gamma)

Remember Energy is increasing from LEFT to RIGHT (Radio to Gamma) Frequency is increasing from LEFT to RIGHT (Radio to Gamma)

Radio have low energy & low frequency longest wavelength (can be as BIG as buildings) communication

Microwave Used for cooking, communication, forecasting the weather, and directing planes at airports Wavelength = size of a honey bee

Infrared Used for heating, Satellite imaging (weather) and operating remote controls Wavelength = size of a pinhead

Visible Light Only waves we can see ROY G. BIV (colors, rainbow) Red = longest wavelength Violet = shortest wavelength

Ultraviolet Causes sunburns Most waves blocked by ozone Weather reports use UV index (1-10) Used in tanning beds Wavelength = size of molecules

X-Ray Allows doctors to view bones Too much exposure is harmful Wavelength = size of atoms

Gamma Highest energy and most dangerous nuclear explosions Used in medicine: kills cancer cells but also healthy cells (hair falls out)

Electromagnetic Spectrum Video xxP0 xxP0 34 minutes

Mr. Parr – Electromagnetic Spectrum

The rest is extra if you need it Balloon experiment which shows that water is a conductor of heat to/perform-cool-water-heat-conduction- experiment / to/perform-cool-water-heat-conduction- experiment /