Download Unit 2 Energy Day 3 2016

Unit 2: Energy Conservation and Transfer
Focus: Fossil Fuels/Nuclear Energy
Day 3: 11/16/16
Science starter - Copy this question:
A student passes a magnet over 10 grams of a powdery substance.
Four grams of the powder stick to the magnet, while 6 grams do not.
Which of these identifies the powdery substance?
Element
Compound
Mixture
Solution
****GO AHEAD AND COPY TODAY’S E.Q. ON
PAGE 33 RIGHT NOW!
You have 2 minutes to answer the
E.Q. on page 31. Go!
Plan for the Day
Group presentation on fossil
fuels/fill in charts
Discussion about Law of Conservation
of Energy
Group presentation on nuclear
energy/fill in charts
Brainpop on nuclear energy
Homework
Due Friday –Make a 3-column
chart comparing and contrasting
FOSSIL FUELS AND NUCLEAR
ENERGY. Give me 4 differences
between them and 4 similarities.
Examples can only be one of the
4 differences. Do this neatly on
a sheet of notebook paper. Use
the full sheet.
Essential Question – What is one negative
environmental consequence of using fossil
fuels and uranium to make electricity?
Let’s hear first from the fossil fuel
group.
Fossil
Fuels
How it works: this is on your chart already; How are they formed: plants &
animals buried for millions of years and changed chemically into coal,
petroleum, and natural gas (mostly carbon); they are taken from the ground
(mining/drilling)
Advantages:
*Convenient-we have the infrastructure (railroads/pipelines) to obtain and
transport them/can build these power plants most anywhere
*Lots of energy released when burned– very efficient (a lot of electricity
from a small amount of coal)
*Add this - Inexpensive
Disadvantages:
*Burning them produces CO2 which may contribute to climate change.
*Cause major air pollution (smog)
*Add this -Mining destroys wide areas of land, habitats; may contaminate
sources of groundwater; may have oil spills
Nonrenewable
Location –large body of water nearby- a cooling pond
In very large cities, the burning of fossil fuels causes air
quality to be so poor that people wear surgical masks to
avoid breathing in the particulates (soot, ash, smoke) and
chemicals in the unhealthy air. This is mostly caused by
the high volume of cars, buses, and other modes of
transportation. Gasoline is made from petroleum (crude
oil). Coal- and oil-burning power plants and other
factories and industries also contribute to this serious
problem.
How would you feel if this were your reality every day?
Applying two science concepts we learned in the
chemistry unit…
1. Why do you suppose coal is pulverized into a fine
powder before it goes into the boiler to be burned and
heat water?
2. Think about the Law of Conservation of Matter. It
says matter (atoms) cannot be created or destroyed, but
it can be changed into different substances. Energy, like
matter, cannot be created or destroyed either, but it can
change form. How does energy change as it goes through
the process of being made into electricity?
The Law of Conservation of Energy
1. Coal has a huge amount of chemical energy stored in it
(from the ancient plant material it’s made of…mostly
carbon).
2. When coal is burned, chemical energy is changed to
thermal energy (heat).
3. When the thermal energy heats the water in the pipes,
the water changes to steam. Steam, under pressure, turns a
turbine. SO, thermal energy is changed to mechanical
energy.
4. The turbine operates an electricity generator, SO,
mechanical energy is changed into electrical energy.
5. Electrical energy is transported to your home along power
lines and allows for all kinds of functions in your home.
****Energy, like matter, cannot be created or destroyed,
but can change form.
Let’s hear from the group on nuclear
energy.
Nuclear Energy
 How it works: atoms of radioactive elements (Uranium and Plutonium) are split
apart through nuclear fission inside a nuclear reactor; heat is produced that
heats water to make steam to turn turbines of generators; taken from the
ground
 Advantages:
*Does not produce air pollution or CO2
*Very efficient- can make huge amounts of electricity this way
*Easy and inexpensive to transport
 Disadvantages:
*generates radioactive waste that is dangerous for thousands of years and
difficult to store
*always the risk of a nuclear meltdown (accident/explosion)
 Nonrenewable
 Location: Large body of water nearby as a cooling pond.
Let’s watch a Brainpop on
Nuclear Energy.
Brainpop Nuclear Energy
Listen for the following:
*Can elements change into other elements? If
so, how?
*What is the process called when atoms are
split to make nuclear energy? What does this
produce?
REMEMBER: The Law of Conservation of
Energy - Energy cannot be created or
destroyed, but can change form.
*Activity: Uranium is mined out of the earth and
used to create electricity. Discuss with your
group the energy changes that occur in this
process from start to finish. In other words, put
these in order:
*thermal energy
*electrical energy
*mechanical energy
*nuclear energy
From the Ground to the Home –
The Process
1. Uranium is mined from the earth.
2. Uranium is placed into fuel rods which are transported to a
nuclear power plant and installed in a nuclear reactor.
3. Inside the reactor, uranium atoms are split through fission.
This releases a lot of heat.
4. The heat is used to boil water and turn it into steam.
5. The steam turns the turbines of generators, and electricity is
made.
The Change
1. Uranium contains nuclear energy.
2. Fission (splitting) of the uranium atoms transforms the nuclear
energy into thermal energy (heat...a lot of heat!).
3. The thermal energy (heat) is transformed into mechanical energy
as steam turns a turbine.
4. The mechanical energy is transformed into electrical energy
(electricity) as the generator operates making electricity.
Work on your 3-column chart.
Wrap-up
o What is the most important
thing you learned today?
Why is this important to you
and your world? Be prepared
to share.