Quick Question: Complete the review worksheet at your table. When you have the correct answers, turn it in.

Objective: I understand the how electricity moves through a circuit.

Electrical Power: Amount of work electricity can do Watts

V= 120 Volts I = 2.2 Amps P = ? P = VI P =120 * 2.2 P = 264 Watts Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? V= 120 Volts I = 2.2 Amps P = ? P = VI P =120 * 2.2 P = 264 Watts

18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power? 18) Luke’s stereo receiver uses a current of 2.2 amps from a 120-volt line. What is its power?

Direct Current: Only flows in 1 direction Example: batteries

Alternating Current: Flow regularly reverses direction Example: Household currents

AC/DC ????

Circuit Diagrams: Show the flow of electricity

Wire & Power Source (battery) Draw A Simple Circuit: Wire & Power Source (battery)

Add Switch:

Add Resistance:

Add Light Bulb

Series Circuit: 1 Path One element doesn’t work, nothing works. The current stops.

Create A Series circuit with a switch, a battery, and 2 light bulbs.

Parallel Circuit: More than 1 path One element doesn’t work, the current goes around it.

Create A Parallel Circuit with a battery, 2 light bulbs, and NO switch.

Create A Parallel Circuit with 3 bulbs, a switch and 2 connected batteries.

Create A Series Circuit with 3 lights, a battery and a switch Create A Series Circuit with 3 lights, a battery and a switch. Label the lamps A, B, & C.

An Electric Highway

Making an Electromagnet Run Current Through A wire

Making an Electromagnet The current creates a magnetic field

Making an Electromagnet Inserting metal rod or more coils increase strength of field

mechanical energy into electricity Generators: Change mechanical energy into electricity

Change Electricity into Motors: Change Electricity into Mechanical energy

Generators & Motors

Making an Electromagnet Can be created using a battery, wire, & nail

Check yourself: Go to: Socrative.com Choose Student login. Enter your true name.

Whiteboard Practice

What is an Electric Charge? An excess of positive or negative charges

What type of circuit is diagramed below? Parallel Circuit

Draw the symbol for resistance used in an electrical diagram.

Find the current of this circuit. V = 24 I = ? R = 6 R = 6 V = 24 volts V = IR 24 = I * 6 4 amp= I Find the current of this circuit.

What type of circuit does this electrical diagram describe? Series circuit.

What determines the potential difference in an electric field? The change in electrical charge from one position to another

Find the voltage of this circuit. I = 2 amp R = 10 V = IR V = 2 * 10 V = 20 volts 10 2 amp Find the voltage of this circuit.

What kind of electrical current flows only in one direction? Direct Current

What would happen if light bulb 3 burned out? 1 What would happen if light bulb 3 burned out? 2 3

What is the transfer of charges without touching called? Induction

V = 120 Volts P = 102 Watts I = ? P = VI 102 = 120 * I I = 0.85 Amps Harley’s television is connected to a 120-volt line. It uses 102 watts of power. How much current flows through it? V = 120 Volts P = 102 Watts I = ? P = VI 102 = 120 * I I = 0.85 Amps

What would happen if light bulb 3 burned out? 1 2 3 What would happen if light bulb 3 burned out?

How does a circuit breaker prevent electrical fires? A switch flips so the circuit can’t be completed

Back to the Future? Hyperlink picture to Back to Future clip

Today’s Objective: I understand changes in an atom’s nucleus that release energy.

Atoms of the same element can have different number of neutrons Atoms of the same element can have different number of neutrons. What are these called? Radioactive: Unstable isotopes because they have too many neutrons in them.

All elements with atomic numbers greater than 83 are radioactive.

* Because their nucleus is unstable, they try to get rid of the things causing it to be unstable. Alpha particles: a helium atom with 2 neutrons Makes atomic number of parent atom two less Can’t pass through paper; Most dangerous in body

Negative charge… Part of neutron Beta particles: emitted by an unstable atom Will penetrate objects but are stopped by wood or thick plastic Negative charge… Part of neutron

high energy x-ray waves Gamma Particle: high energy x-ray waves Only stopped by very thick lead

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Radioactive Decay: Process where atoms give off alpha particles, beta particles, or gamma rays Becomes a different element

Half-life: The length of time it takes ½ of the atoms in a radioactive sample to decay and become a different element.

Thallium-208 has a half-life of 3.053 min. What fraction of a sample of Thallium-208 will be radioactive after 2 half-lives?

Thallium-208 has a half-life of 3. 053 min Thallium-208 has a half-life of 3.053 min. After 10 minutes, how much of a 25 gram sample of Thallium-208 will be radioactive?

Thallium-208 has a half-life of 3. 053 min Thallium-208 has a half-life of 3.053 min. How long will it take for 120.0 g to decay to 7.50 g?

Balancing Nuclear Equations: Even with nuclear reactions, mass must be accounted for.

Nuclear Notation for alpha particle: 4 2 Mass Number He Atomic Number

A balance a nuclear equation for alpha decay of polonium-210. 1) List info given: Po-210 2) Write parent isotope using nuclear notation: 210 Po 84

3) List unknowns: Z = Atomic # of daughter A = Mass # of daughter X = Chemical symbol of daughter

4) Write the equation containing the information. Po X + + 84 Z 5) Write and solve the equation for mass. 210 = A + 4 210 – 4 = A 206 = A

6) Write and solve the equation for atomic number. 84 = Z + 2 84-2 = Z 82 = Z 7) Use the periodic table to determine the element with an atomic number of 82. 82 is lead so X is Pb.

8) Write the balanced nuclear equation: 210 206 4 Po  Pb + He 84 82 2 9) Check your work. The mass number on the left equals the sum of the mass numbers on the right. The atomic number on the left equals the sum of the atomic numbers on the right.

Assignment: Page 295 Math Practice 1-4 Turn in before you leave today.