ingridscience

Before the lesson, arrange the devices throughout the classroom so that the students can walk around to visit each. Add a visible card next to each, so that they can find each device or item. Ideally the devices are functional e.g. the fan is blowing, the light bulb is on, the speaker is playing music.

Review types of energy with students:
gravitational potential energy is the energy stored in an object when it is high
kinetic energy (also called motion or mechanical energy) is the energy an object has when it is moving
heat (thermal energy) is the energy in something warm (the total vibrational movement of the molecules is the heat of a material)
sound energy we can hear as noises
light energy is the energy in light emitted from an object
nuclear energy is the energy contained in the nucleus of an atom
electrical energy is the energy carried by electricity
chemical energy is the energy contained in the chemistry (i.e. the molecules) of an object or living thing, often created and released through chemical reactions
elastic potential energy is the energy stored in something that is stretched (before it returns to its unstretched state)
magnetic energy is sometimes also listed as a stored energy in magnets

Students visit each device and record on their worksheet the type of energy they think makes the device work (i.e. the input energy) and what kind of energy it produces (i.e. the output energy). They draw a line from an energy input type on the left to energy output type on the right, then write the name of the device/object on the line. There may be more than one kind of energy produced by a device, and more than one kind of energy may make a device function. They may not use all the energy types on their worksheet. Try and focus students on the input energy that is the last energy to enter the device, and the output energy that the device is intended to produce. They can make notes on other kinds of energy that are unintended output energies (often heat and sound).

Discuss their results.
There are often no wrong answers, as students will see many of the ways that devices function. Students may also make educated guesses as to how devices work (e.g. is there a magnet it there that makes it work?) - encourage discussion around these ideas.

List of devices/objects with likely energy inputs and outputs:
fan: electrical in, motion (of the air molecules) out
light bulb: electrical in, light out. heat is often also an output energy of lightbulbs, so making them less efficient
speaker: electrical in, sound out
kettle: electrical in, heat out (also sound out)
telephone: sound in (also motion in as you dial the number), electrical out
battery: chemical in, electrical out
candle: chemical in, light (and heat) out
magnetic stripe card: magnetic in (of the encoded magnetic pattern in the stripe), also motion in as you swipe it, electrical out (as the card communicates with the card reader)
ukulele (or other stringed instrument): elastic potential energy (of the stretched string) and motion energy (of the hand strumming) in, sound out
elevator: electrical in, gravitational potential and motion energy out
plant:light (of the sun) and chemical (of the minerals and water) in, chemical out (as the plant grows by building up chemical structures)

Discussion around electrical energy production and renewable energy
Students may notice that many of the devices require electricity as an energy input. This can lead to discussion around how we produce electricity.

• Fossil fuels (coal, oil, natural gas) are used extensively for energy production. The fuel is burned to make heat, which is used to boil water and make steam (chemical energy to heat energy to motion energy). The steam is channeled over turbines, which turn with the movement of the steam (motion energy). Turbines are connected to generators to make electricity (motion energy to electrical energy). When the fuels are burned they produce carbon dioxide, which is a greenhouse gas, so contributing to global warming.
• Nuclear power uses the energy contained in a uranium atom. Uranium atoms are split to make heat. The heat is used to heat water and make steam which flows over turbines which powers generators to make electricity. Nuclear power stations can be built safely, but the nuclear waste from this kind of energy production is a problem.

Optional: to help understand how generators work, demonstrate a motor. A motor is a wire with a current through it next to a magnet, and the forces combine to make the wire move. A generator is the reverse: a wire made to move next to a magnet produces a current in it, which is electricity.

Renewable energy sources are becoming more common, with the urgency to curtail global warming.

• Solar power is the conversion of light to electrical energy. Photovoltaic (PV) cells make up solar panels which convert light directly to electricity. Concentrated solar power (CSP) concentrates sunlight to make enough heat to drive a steam turbine and electricity generator.
• Hydroelectric power uses the gravitational potential energy of water behind a dam to drive turbines as it falls, which are hooked to generators. This is the most common renewable energy. Dams can be negative in that they flood whole ecosystems and maybe human communities, but they can also be positive in making a reservoir for areas that have long periods of drought.
• Wind energy uses the motion of wind to turn turbines, which are connected to generators.
• Geothermal energy uses the heat energy deep in the earth. Pipes running deep underground and up again (called geothermal heat pumps) can bring the heat to the surface, where it can be used directly to heat buildings. Alternatively, steam is either collected from underground, or made by injecting water into the warmth underground. Above ground, the steam drives turbines and generators. Iceland uses 90% geothermal heating.
• Wave energy uses the motion of the waves to drive turbines.
• Tidal energy uses the rising tide to fill a reservoir, from which water can later fall to drive a turbine.
• Biomass energy (or Bioenergy) is the method of burning organic matter to make heat for steam that drives steam turbines. Vegetable oil crops, algae, compost, mature, methane from cow farts are kinds of biomass used for this kind of energy production.
• Salt and temperature gradients in the ocean can be used for making energy

See https://www.nationalgeographic.org/encyclopedia/renewable-energy/
https://www.environmentalscience.org/renewable-energy

Peel/chop fruits and veggies, to collect small pieces of coloured material.
Add to the mortar and pestle with very little water and crush to make a concentrated coloured liquid.
Pour a little of the coloured liquid into wells of the tray.
Add drops of acid and base to change the colour (or not - results are very variable).

This activity models how sedimentary rock layers are formed, and then uplifted.
Optionally, paper fossils can be added to the sedimentary layers, to model how fossils are exposed as uplifting and erosion occurs.

Demonstrate making the sedimentary layers (just two or three, before students' turn):
Layer the sand and sugar alternately in the container. It seems to work best if the lighter sugar layers are about 1cm deep and the dark sand layers are 1-2mm deep. Make at least three layers of each, depending on the container size.
This step models how sediment is carried by water and wind, to build up in layers in oceans, lakes and deserts.
As layers add on the top, the lower layers are compressed, eventually forming sedimentary rock as they get deep enough.

Modelling fossil formation:
Sometimes when an animal or plant dies it falls into the sediment.
If adding fossils to the model, add the oldest fossil e.g. Trilobite to one of the bottom layers (Trolobites lived 500 Mya to 250 Mya; Cambrian through Permian). Add a more recent fossil to the layer below the top layer e.g. Pterosaur (Pterosaurs lived 200Mya to 65Mya; Triassic through Cretaceous). See last two photos.
Hard animal body parts such as bones and shells are preserved in the sediment and are slowly turned into rock. Hard plant parts can be preserved, or plants make impressions (prints) between rock layers.

Students make their sedimentary layers, optionally adding fossils.

Demonstrate uplifting:
Hold the cardboard paddle upright and push it to the bottom of the container of sedimentary layers, at one end. Slowly slide the cardboard along the container, making sure that it stays touching the bottom as it moves. Try and move it as smoothly as possible.
Sand and sugar may spill out of the top of the container. Watch through the side as the layers buckle and fold.
Stop the uplifting when the folds are clear before they start getting muddled up - when the cardboard paddle is about half way along the container. Then add lightly crumpled sheets of tissue to hold the paddle upright in place.
The sand and sugar spilling from the top of the container mimics erosion - the top of a mountain is worn away by wind and water - exposing lower layers of rock.

Students uplift their sedimentary layers.

Modelling fossil discovery:
If fossils have been added, the more recent fossils in the higher sedimentary layers are exposed as the top layers erode away (fall off the top of the model). The lower layers with their older fossils will likely remain hidden.
Older fossils in real rock are harder to find as they are more rarely exposed, while the newer fossils are more frequently revealed as sedimentary uplifting occurs. A fossil is dated by the age of the sedimentary rock layer in which it is found.
Note that real fossils do not just fall out of the rock. Once a part of a fossil is exposed by erosion, geologists carefully chip and brush around it before lifting the fossil out of the rock.
Using fossils, scientists can construct a map of what life forms existed at what times. Fossils show a gradual change of how living things look through time, over millions of years.
Fossils have shown how life moved onto land (Tetrapods), how whales evolved from land mammals, and reveal missing links (Archaeopteryx is the missing link between dinosaurs and birds).

Study the folding patterns:
Allow students to visit all of the models, to see the different patterns of folding.
Students can optionally use the attached worksheet to draw the shapes of the folds in models of their choice.
Pick out a couple of examples to bring to group discussion.
Show images of real sedimentary folds. Try https://www.geologyin.com/2016/09/10-amazing-geological-folds-you-shoul… or https://www.easternct.edu/cunninghamw/ees-356-teaching-resources/struct…
Ask students to find the same folding patterns in their models as in the images.
Just as in their models, real sedimentary rock layers are folded and buckled upwards as tectonic plates converge, move under and over each other. When plates collide and slide past each other, earthquakes happen.
The Alps and Himalayas were formed over 10s of millions of years - the Alps from the African and Eurasian tectonic plates colliding and the Himalayan Mountains from the convergence of the Indian and Eurasian plates. At the summit of Mount Everest there is marine limestone.
The Canadian Rockies were formed when the tectonic plate of the Pacific Ocean pushed under (subduction) the continent, causing it to wrinkle upwards.

Ask students to stand in a wide circle around you, or stand in a clearing in the centre of the classroom.

Turn on the tone generator (e.g. an application on your phone), set to about 550Hz, and check that students can hear it.

Put the phone in the bag.
Tie the string around the handles.
Spin around your head (letting out the string longer as you speed up).
Make sure everyone is silent so that students can hear the tone of the note getting higher and lower as it respectively comes towards and away from them.

Explain that this change in frequency of a sound is called the Doppler effect.
It is happening because the note of the sound changes with how close the sound waves are together. Closer waves have a higher note and waves spaced further apart have a lower note.
When the source of the sound is moving towards you, the source catches up with the sound wave that was just emitted, so that the next wave is a little closer to the preceding one. Hence when the waves reach our ear from a source coming towards us, they are all closer together and sound higher.
When the source of the sound is moving away, the waves are emitted from a further and further distance away, so the waves are spaced further apart, hence sound lower.

Also heard with a car horn on while driving by. Find on youtube e.g. hear a car horn passing at https://www.youtube.com/watch?v=a3RfULw7aAY

Students start by mixing each of the materials in turn with water. then using the key on the worksheet to find out what kind of mixture they have made.
Ensure that they only add a small amount of powder and fill the little pot most of the way with water. They shake hard for 10 seconds, then immediately look for particles of the material settling on the bottom. If particles do settle, they have made a suspension. If no particles settle, they should look for whether the mixture is clear or not. If it is, they have made a solution. If it is not clear, they have made a colloid.

Once students have tried all the substances individually with water, discuss the properties of each:
A suspension has clumps of one material in another. The clumps are large enough to be pulled down by gravity and settle on the bottom. Sand in water should act in this way, and also flour in water if a lot is added.
A solution will not have any particles large enough to settle. Their molecules are completely evenly mixed together. Light can pass through a solution so it looks clear - this is because individual molecule is too small to block light. Baking soda and sugar form solutions. (If students add enough sugar or baking soda, some will not dissolve and will settle to the bottom, so making a suspension.
A colloid has small clumps of one material in another (e.g. milk in water or flour in water). The clumps are not large enough to settle out, so they stay suspended in the liquid. The particles are large enough to block light, so a colloid does not let light pass through, and looks cloudy. If students add enough flour or milk powder, some may settle on the bottom and be classified as a suspension.

Optional: to see the tiny particles of a colloid under a microscope, make a slide of milk (2% works well) and view through a transmission scope at 100X or 400X. You can see the variously-sized fat droplets floating in the liquid water and other substances (sugars, proteins).
Optional extension: point out the jiggling motion of the fat droplets due to Brownian motion.

Relate to familiar mixtures:
suspension - silt in a river is deposited. Sedimentation is used to treat water for drinking - contaminants are coagulated first, then filtration is used to separate the clumps out.
colloid - milk. other oil in water - salad dressing.
solution - salt, coffee, apple juice - various molecules in solution with water

Allow free play time for students to mix the materials together as they wish, followed by discussion of the mixtures they made, and why those combinations of molecules behave in that way.
They will like to make dough, by adding a lot of flour and maybe other ingredients to a little water. The long flour molecules form a dense mat which thickens up the water to form the texture of the dough.
They may notice different particles settling at different rates - the larger ones (likely sand particles) should settle more quickly. This same separation happens on stream beds.

Ask students to place one hand in the cold water and one hand in the very warm water, and leave them there for at least one minute.
Then place both hands in the medium temperature water. What temperature does each hand feel? (I found it easier to place one hand at a time in the medium temperature water, as the different sensations coming from each hand make it hard for the brain to process what is going on in each hand.)

Students should find that the hand that was in the cold water will feel warm, and the hand that was in the warm water feels cold.
The temperature receptors, called "thermoreceptors" in your hand detect temperature changes, and signal that change to your brain. After a while in water of one temperature, they get used to that temperature, and on being immersed in a different temperature signal the relative change in temperature. Hence the colder hand feels warmer, and the warmer hand feels colder, even thought they are both immersed in the same temperature.

Here is more detail on the receptors that detect temperature:
We have both cold thermoreceptors that are activated by cold, and warm thermoreceptors that are activated by heat. Cold receptors fire more signals when they are cooled, and decrease the signals sent during warming. Warm receptors increase signal rate when they feel warmth and decreased signal rate on cooling. But, in addition, either thermoreceptor, when exposed to the same temperature for a while, will tire and stop sending signals about the temperature. Hence the hand that gets used to cold has cold receptors that are tired, so when it enters the medium water only the warm receptors will fire. By contrast, in the hand that gets used to warm, the warm receptors have become tired, and when the hand enters the medium water only the cold receptors will fire. Hence different signals are sent about the same temperature water.

Test seawater for pH (it is generally pH 8 or basic).
Compare to drinking water (neutral or slightly acidic/basic).
Compare to stream water, pond water and fish tank water (usually neutral).
Students might also want to test the pH of their spit (neutral).

Water chemistry varies with the kind of rock that the water flows over/through, and the chemicals that are added during treatment.

Ocean water becomes more acidic as more carbon dioxide dissolves in it, which happens as the atmospheric carbon dioxide goes up.

Vancouver drinking water is from North Vancouver watersheds, and is naturally slightly acidic. The treatment process makes it a little higher pH.

From Metro Vancovuer website 2021:
Metro Vancouver currently delivers water with a pH of 7.7.
Adjusting the pH is an existing key component of Metro Vancouver’s water treatment process because our untreated source water is naturally slightly acidic. Increasing the pH to a target range of 8.3 to 8.5 will:
• Reduce the release of copper from pipes in buildings caused by low pH in the region’s water;
• Reduce leaks in pipes caused by copper corrosion;
• Help preserve the lifespan of pipes and hot water tanks; and
• Reduce green stains on tubs, sinks, and grout.

Sorting feathers:
Feathers can be sorted into types. The wing and tail feathers are long. The tail feathers have the hard tube or 'rachis' up the middle. On wing feathers the rachis is to one side. Both of these kind of feathers are used to push air and help the bird fly and change direction.
Body feathers have fluffy barbs at the bottom of the feather which are for trapping air and insulating the bird.

See these images for feather types: https://www.birdsoutsidemywindow.org/2019/12/17/how-to-identify-feather… (second image) or https://academy.allaboutbirds.org/wp-content/uploads/Bird_Biology-feath… (from https://academy.allaboutbirds.org/feathers-article/)
See these images for which feathers are on which parts of a bird: https://www.researchgate.net/figure/Structures-morphotypes-and-body-pos…

Looking at feather structure:
On a long wing or tail feather, gently pull the barbs (the hairs coming off the shaft), until they pull apart, then stroke them back together again.
The barbs have little hooks (called barbules) that zip together and keep the feather in a flat plane. The flat plane can push air and help the bird fly and change direction.
Look closely at feathers under the magnifier and microscope. Find the interlocking barbules along the barbs.
Feather structure diagram: https://www.britannica.com/science/feather

Fluffy downy feathers do not have barbules. Their barbs float apart and form air pockets that are excellent for insulation.

When birds preen, they pull their feathers through their beak to zip barbs together again.
They also add oil, so that the feathers are waterproof.

Light the paper and drop it into the bottle.
As it goes out place the egg on the top of the bottle.

As the air in the bottle cools again and contracts, the low pressure in the bottle pulls the egg into it.