Transcript Misconceptions still abound Questions relating to climate change ATSE 2011 Keith Ross Student teachers come to us still with many scientific ideas unclear, unchallenged and in.

Misconceptions still abound
Questions relating to climate change
ATSE 2011
Keith Ross
Student teachers come to us still with many
scientific ideas unclear, unchallenged and
in need of review.
ESCalate http://escalate.ac.uk/1141.
The big ideas
• On Earth matter is cycled whereas energy is degraded
• Gases are made of matter – the atmosphere is ‘heavy’ and held
in place by gravity
• Energy from sun arrives as visible light and escapes as IR.
There is a balance. Water vapour and other gases help make
the atmosphere like a natural greenhouse
• Life processes recycle their carbon so CO2 does not build up in
the atmosphere
• Fossil fuel carbon, released into the atmosphere during
combustion, increases CO2 levels, so less easy for IR to
escape. Earth has to heat up to restore the balance.
Understanding matter and
energy
When something is dumped on the
rubbish tip, goes up the chimney or
down the drain:
True or false:- Its atoms may….
a. … be used by living things to help them grow.
b. … remain in the environment and cause
pollution.
c. … remain harmlessly in the environment.
d. … eventually cease to exist.
Suppose you weighed all the consumer material
that enters a typical house (air, water, gas, food,
packaging etc) during a year and then you weighed
all the material that left the home over the same
period (gases up the chimney, through windows
etc, liquids & solids down the drain, solid waste into
the bin etc.)
Would the materials leaving weigh:
a. A lot more than …
b. About the same as …
c. Much less than … the material entering
the house
If you were to measure all the energy entering a
house over a year (sunlight, heat, energy
transferred from burning fuels, electricity, energy
from respiration etc.) then you measure all the
energy leaving the house over the same period (up
the chimney, through the walls, roof, windows etc.
as heat, sound light etc.) ...
... would the energy leaving the house be...
a. A lot more than …
b. About the same as …
c. Much less than … the energy entering
the house
A car made a round trip yesterday. Twenty litres of
fuel were used, and the fuel tank is now empty.
Where is the energy (measured in joules) today,
obtained from combustion of the 20 litres of fuel
during the trip?
The energy (in joules):
a. has been dissipated as environmental heat.
b. was used up fighting against air resistance etc.
c. has been stored and is available for use later
on.
d. has not been used up, but transferred into
sound, air movement, heat etc.
A cyclist completed a round trip of 20 miles
yesterday. What has happened to the usefulness of
the energy today, that was released from the
working of her muscles during the ride, and which
'fuelled' the round trip?
The usefulness of the energy:
(Note that this is a different question.)
a. is still there as sound, air movement, and heat energy in
the tyres and brakes which the cyclist can use again.
b. has been stored and is available to be used later on by
the cyclist
c. has gone fighting against air resistance etc
d. is still there as environmental heat which the cyclist can
use again
Which of the following is/are
powered, directly or indirectly, by
replenishable energy from the
sun?
a.
b.
c.
d.
a bicycle (with rider)
a hydro-electric power-station
a wood fuel stove
a windmill
Consider the following
statements about replenishable
energy sources.
True or false:
a. They are almost all continually
replenished by solar energy.
b. In the distant past people relied on them
for cooking, farming and transport.
When a car is being driven at a
constant 60mph along a flat road
what percentage of energy is used
to provide kinetic energy to the car?
a.
b.
c.
d.
e.
None
A little
Half
Most
All
Which one of the following best explains why
it is more costly in energy for a train to stop at
all stations rather than travel at a constant
speed for a journey?
a. Energy is used to operate the brakes
b. More energy is needed to overcome friction
when you keep stopping and starting
c. Fresh inputs of kinetic energy have to be used
after each stop
Understanding gravity, gases
and the atmosphere
A football is about to be pumped
up with air. Who is right:
a. I think it will get heavier.
b. I don't think the weight will change.
c. I think it will get lighter
Which of the following statements
about the force of gravity are true?
Gravity:
a. Pulls things down to the earth
b. Is caused by air pressing on us
c. Exists on the moon as well as
on the earth
d. Pulls together two objects which
have mass
An astronaut is standing on the moon. She releases
a feather and spanner together from the same
height above the surface of the moon.
Which of the following describes what happens?
a. The feather reaches the ground first.
b. They travel together but with
increasing speed (acceleration)
c. They travel together at constant speed
(terminal velocity).
d. The spanner reaches the ground first.
Which two of the following are
good explanations of why a hot
air balloon rises?
a.
b.
c.
d.
Hot air always rises.
Cold air pushes it up.
Gravity no longer acts on the hot air.
Hot air is buoyed up by the rest of the air.
Understanding the Greenhouse
effect
True or false:
The 'hole' in the ozone layer:
a. lets heat in and causes global warming
b. lets UV in and causes a possible
increase in skin cancers
c. It is caused mainly by substances that
are inert (unreactive) at ground level
d. It would eventually repair itself naturally if
left alone
True or false:
Energy from the sun:
a. is the energy source that fuels living things
b. reaches us in the form of electromagnetic
radiation
c. is absorbed directly by the atmosphere,
causing the enhanced greenhouse effect.
d. is the energy source that fuels the weather and
climate
Understanding the carbon
cycle
Consider the material (stuff, matter, atoms. . .) in
our food that enters our blood and which we have
used as a fuel (providing us with energy).
Which one of the following describes how this
material (ie the stuff, matter, atoms)
leaves our body?
a.
b.
c.
d.
It comes out as energy, eg movement and heat.
It comes out as faeces.
We breathe a lot of it out as carbon dioxide and water
vapour.
The atoms are all used up and only energy is left.
When do plants respire?
a.
b.
c.
d.
All the time
At night only
In the daytime only
Never
Which of the following are required
by all germinating seeds?
a. Oxygen
b. Water
c. Carbon dioxide
d. Light
e. Minerals
f. Soil
g. Warmth
What is the immediate source of
energy for a seed to germinate?
a.
b.
c.
d.
The sun
Carbon dioxide and water
Respiration of starch in endosperm
The embryo
Which of the following are sources
of energy for a plant to grow?
a. Sunlight through photosynthesis
b. Carbon dioxide and water through
photosynthesis
c. Glucose and oxygen through respiration
d. Minerals taken up through the soil
Which of the following
statements are true?
a. Breathing helps get oxygen to the lungs
b. Breathing is a simpler term for respiration
c. Digestion is where food turns to energy
d. Digestion helps get nutrients into the
blood
e. Respiration happens in the lungs
f. Respiration occurs in the cells of our
bodies
Which of the following are ways your
body removes the waste products
produced by chemical reactions in your
cells?
a. The lungs remove Carbon dioxide from the
blood
b. Faeces are removed via the anus
c. Blood is filtered by the kidney and waste
removed as urine
d. Some material is lost in sweat
e. It is excreted
What will happen to the weight
of a fertilised bird's egg as the
chick develops?
a. It gets heavier
b. It gets lighter
c. It stays much the same
Natural organic materials like paper, wool,
leather and cotton rot if they are thrown
away, but artificial organic materials such as
polythene and nylon do not.
This is because:
a. Man-made things are waterproof so cannot rot.
b. Natural materials are chemically completely different
and only they can rot.
c. Man-made fibres are stronger than the fibres in
natural materials.
d. Microbes have not yet evolved to deal with manmade materials.
Understanding fuels and
burning
Many people say that fuels contain
energy.
How do you imagine energy to be
associated with, or to be 'in', fuels?
True or false:
a) When fuels burn the energy trapped in
them is released.
b) The energy is not in the fuel itself, but is
associated with both the fuel and oxygen.
What is the origin of the energy which is
transferred when fuel burns:
True or false:
a. Fuels contain energy-rich bonds
which release energy when the
bonds break.
b. Energy is released when new bonds
are formed. This happens during
burning.
Suppose you collect everything that comes out of
the exhaust pipe of a car on a journey (exhaust gas,
fumes, etc.) and somehow press it all together so it
can be weighed.
Compared to the amount (weight) of petrol used for
the journey, the amount (weight) of exhaust
(everything that comes out of the exhaust pipe) will
be (choose one):
a.
b.
c.
d.
Much lighter because the petrol has been burnt up.
Much lighter
? because gases don't weigh anything.
About the same because atoms cannot be destroyed.
Much heavier because air has been added to the
petrol.
Contacts - links
• [email protected]
• www.scienceissues.org.uk
• http://escalate.ac.uk/1141
• www.ase.org.uk/resources/scitutors
• Teaching Secondary Science – 3rd Edition
Ross, Lakin & McKechnie – Routledge 2010