ingridscience

Hummer

Summary
Make a hummer, and figure out how the sound is made.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Materials
  • popsicle stick
  • two erasers that fit on the end of a pencil
  • index card
  • scissors
  • stapler
  • string, about 80cm
  • wide rubber band #64
Procedure

Students can be instructed on how to make the hummer, or ask them to look at a model and figure out how to make it themselves (skills in careful observation, trial and error testing).

Put the erasers on the end of the posicle stick.
Cut the index card so that it fits between the erasers, then staple it to the popsicle stick.
Tie the string onto the posicle stick, beside the index card.
Stretch the rubber band around the erasers.
Hold the end of the string and swing the hummer around your head.

Instructions at:
http://www.exploratorium.edu/afterschool/activities/index.php?activity=…

Tip: the rubber band must be flat (not twisted) for this to work.

Discuss how the sound is made:
As the hummer moves it makes the rubber band vibrate. The index card amplifies the sound.

Students can try changing the rubber band to see how it changes the sound.

Notes

When trying different rubber bands, the flat ones seem to work best.
Not sure why sometimes two notes are heard - maybe harmonics?
Instead of erasers, use corks or tape.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4

Erosion and Weathering by Wind, Water (and Ice)

Summary
Students explore erosion by wind. Demonstrate erosion by water and ice. Demonstrate weathering by rock collisions.
Curriculum connection (2005 science topic)
Life Science: Needs of Living Things (grade 1)
Life Science: Animal Growth and Changes (grade 2)
Life Science: Habitats and Communities (grade 4)
Life Science: Diversity of Life (grade 6)
Life Science: Ecosystems (grade 7)
Materials
  • materials in the activities
  • white modelling clay to shape into a glacier
Procedure

Introduce/review weathering and erosion:
'Weathering' is wearing rock into small particles. 'Erosion' is the movement of those particles.
Weathering and Erosion wear away landforms and make new ones.
Wind, water and ice all cause weathering and erosion.

Wind, water and ice all cause rocks to collide with each other: the wind blows small grains into rocks, water on a beach crashes rocks together, ice in a glacier grinds rocks together underneath it as it moves.
Show students rocks that will be added to the tumbler, and draw around them, and write in rock types, to record their sizes and shapes.
Suggested rocks local to Vancouver: granite and basalt (intrusive and extrusive igneous respectively), sandstone and mudstone (sedimentary).

Optional: Add rocks to the rock tumbler as soon as possible, so that it can tumble for close to an hour.
We’ll see what happens as those rocks collide in the rock tumbler. We’ll only tumble it for an hour. Wind, water and ice in Earth's landscapes bang rocks together for much much longer than this.

Erosion of a mountainside by water demonstration.

Erosion by ice:
Using the same water erosion tray, find a part of the mountainside that has not been washed away.
Mould the white modeling clay into a long, wide glacier shape.
Push the 'glacier' through the mountainside, showing how it gouges out the landscape. As the ice of a glacier is slowly pulled down the valley by gravity, rocks are frozen into it and are plucked from the surface. The rocks and pebbles stuck in the ice scrape at the ground, eroding it.
Ice is the most powerful erosive force.
When a glacier retreats (melts), it leaves a U-shaped valley, with a flat bottom and steep sides. Image of a valley formed by a glacier: https://learning.royalbcmuseum.bc.ca/pathways/alpine-plants/image-5-u-s…

Wind erosion activity, with challenges and free play, to see how wind shapes a desert landscape.

Rock tumbler revisit:
Look at the rocks in the tumbler, to see what has happened in just an hour.
Pull rocks from tumbler, dip in water to rinse off, and lay on the same labelled paper for sizing again.
Even in an hour, the softer rocks should be starting to break apart into smaller pieces.
Any the mud in the tumbler is from small bits that have fallen off the rocks mixing with the water.
Discussion:
Wind, water and ice cause rocks to crash into each other, breaking them into smaller pieces.

Summary of lesson:
Weathering and Erosion by water, and ice and wind change the shape of our landscape.

Grades taught
Gr 1
Gr 2
Gr 3

Animal parts collection

Summary
Use a collection of animal parts (bones, shell, teeth, antlers) and/or live animals to study evolution, adaptation, comparative anatomy etc
Science topic (2005 curriculum connection)
Life Science: Animal Growth and Changes (grade 2)
Life Science: Plant Growth and Changes (grade 3)
Life Science: Habitats and Communities (grade 4)
Life Science: Diversity of Life (grade 6)
Life Science: Ecosystems (grade 7)
Materials
  • collection of animal parts e.g. antlers, feather, shell
  • if possible, live animals to observe e.g. gerbils or other caged pet, fish, snake, lizard, worms, wood bugs
Procedure

Look at each animal part, and discuss it as an adaptation for the animal.
Look at the living animals, and ask students to note parts of its body that is an adaptation to its environment.

Antlers:
After laying the antlers on the table, ask the students what they are. Who they are from.
Students can carefully lift them to experience how heavy they are. How does a moose carry around that weight?
Use questions of students, along with asking them to notice features to lead discussion on antler formation and function
e.g. blood vessel lines: antlers were first cartilage covered in a skin with blood, then replaced by bone.
e.g. nibbled part provided calcium for other animals.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4

Natural selection game

Summary
A group of students act as coyotes, rabbits and grass that catch and "eat" each other, to model a food chain in action, and to show natural selection driving population changes.
Science topic (2005 curriculum connection)
Life Science: Needs of Living Things (grade 1)
Life Science: Habitats and Communities (grade 4)
Life Science: Diversity of Life (grade 6)
Life Science: Ecosystems (grade 7)
Materials
  • ears e.g. pipe cleaners bent into ears attached to a dollar store headband, one for each student
  • rope or cones to define the coyotes' territory
  • clothes pegs or other clips, to represent mutations
  • outdoors or gym space
Procedure

Give the students their ears.
When their ears are on their head they are a coyote.
To be a rabbit, students turn one of the ears down, floppy bunny ear-style.
To be grass, students put their ears around their necks out of the way, squat down and put their fingers up like blades of grass.

Divide the students into different species for the first round of the game: about 10% of them are coyotes (wearing ears); the rest of them split between rabbits (with floppy bunny ears) and grass (ears around necks and fingers up).
Divide the area into three parts. The coyote territory is in the middle, the rabbits on one side, the grass on the other side.

When the teacher signals the start of a day (or more realistically, a month), the rabbits try and run across the coyotes territory to get to the grass. The coyotes try and catch them by tagging them as they run across. If a rabbit does make it across the coyote territory, it needs to find a grass of its own.

Initially at least, once the rabbits have made it across, or not, the teacher signals the end of the day, and the class discusses what has happened and resets the characters as follows:
If a rabbit is caught by a coyote, the coyote gets to eat and reproduce: the rabbit becomes a coyote for the next round.
If the rabbit makes it across the coyotes’ territory, and finds its own grass to eat, it reproduces: the grass it pairs with becomes a rabbit for the next round.
If a coyote does not catch a rabbit, or a rabbit does not find their own grass, they die, and recycle into the earth: they become grass for the next round.
At the end of the round, all rabbits walk back across the coyote territory unchallenged to their starting side.
If the students get the hang of becoming a new species each round, try running the game continuously: they switch out their ears/tail/grass as they become a new species each time. Rabbits can walk back across the coyote territory unchallenged before attempting to run across without being caught to reach the grass.

Run the game for several rounds, maybe stopping earlier if one of the living things dies out (or not - to see how the other populations are affected).
Discuss what happened: the individuals that are able to eat can reproduce. If there are a lot of one species, the food that they eat becomes depleted, then there is competition for the less food available, and not as many of that species are able to eat and survive, so their population decreases again. This game shows population changes in action. Sometimes a species may die out, and the populations of the other species it interacts with in the food chain take over.

Add in an adaptation, showing natural selection:
One rabbit gets a random mutation in its DNA that makes it run a little faster than the other rabbits. Signify this by adding a clip or other marker to the headband of one rabbit. In the game this rabbit with a mutation gets to cross the coyote's territory without being tagged. If it finds its own grass it can reproduce to make another rabbit, also with the "fast" mutation (add a clip to the headband).
As the days past by, more and more of the rabbits that survive have the fast mutation. It is a beneficial adaptation that has spread through the population. This shows natural selection - how beneficial mutations are selected for.

Discuss other adaptations in coyotes and rabbits that help them survive:
The coyotes have teeth and claws to catch their prey, large ears and good noses to locate prey etc
The rabbits have long legs to escape from predators, also large ears to listen out for danger etc
Both animals are camouflaged to blend in with their surroundings. For the rabbit, a prey animal, it can hide in the grass better and not be spotted by a coyote. Coyotes are camouflaged so that they can sneak closer their prey without being seen by them.

Notes

Other natural selection games online:
https://online.ucpress.edu/abt/article/82/2/104/109715/The-Natural-Sele… (more compex with alleles, but could be adapted)

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6
Gr 7

Gas pressure

Summary
Increase the pressure of a gas to make popcorn and set off a rocket.
Curriculum connection (2005 science topic)
Physical Science: Force and Motion (grade 1)
Physical Science: Properties of Matter (grade 2)
Physical Science: Chemistry (grade 7)
Materials
  • balloon
  • all materials in activities
Procedure

Introduction to gas pressure:
The air is made of gas. Many many tiny particles, too small to see, bumping each other and the walls.
If we squeeze some gas particles into a balloon, they are still bumping around, but as there are more of them, they bump the sides of the balloon, and push against it - that is pressure - the pushing. If we blow the balloon up too much, the pressure is too much for the balloon and it bursts.

The pressure also makes popcorn pop.
Make popcorn (or start earlier if it takes a while).
Optional: draw popped and un-popped kernels.
Show slow-motion popcorn-popping video to each table, and check drawings.
Ask students why the popcorn pops - prompt if needed that popcorn contains water that is heated to a gas... which expands... and puts pressure on the husk of the kernal... until it pops.

We will now use gas pressure to make a toy.
Show how to make a stomp rocket.
Draw your rocket and launcher, showing with arrows and words where the gas pressure is created, and where it travels to shoot the rocket.
Optional: add fins decorate rocket.

Notes

Add bottle rocket if time for a powerful rocket demonstration.

Pressure also demonstrated in film canister rocket and baking soda/vinegar rocket demonstration, which use a chemical reaction to generate gas pressure.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4

Stomp rocket

Summary
Make a stomp rocket. Discuss the forces/gas pressure that makes it fire.
Science topic (2005 curriculum connection)
Physical Science: Force and Motion (grade 1)
Physical Science: Forces and Simple Machines (grade 5)
Physical Science: Chemistry (grade 7)
Materials
  • cardstock
  • stiff tube, about 12” long (1” diameter or less) e.g. 1/2" PVC water piping works great, other stiff plastic piping, or try the inside cardboard tube of a roll of aluminum foil/cling wrap
  • packing tape
  • bike inner tube, half a round (best width 1.0/1.5", max width 1.5/1.75", wider won't work nearly as well) OR flexible PVC tubing (3/8")
  • empty water bottle, thinner crinkly plastic personal size (500 ml) work well and last
  • duct tape
Procedure

To make the rocket:
Roll the cardstock snugly around the stiff tube, then tape along its length to make it into a tube. Slide the cardstock tube off, flatten one end, and tape it closed with packing tape. Optional now or after launching a few times: decorate/add rocket fins etc.
To make the launcher:
Pull the bike inner tube over the mouth of the plastic bottle and secure with duct tape. (Or push the PVC tubing inside the mouth of the bottle and secure with duct tape.)
Pull the other end of the inner tube over one end of the stiff tube and secure with duct tape. (Or push the other end of the PVC tubing inside the stiff tube and secure with duct tape.)

To launch:
Take the rocket outside, or into a gym/hallway with a high ceiling.
Slide the cardstock rocket over the stiff tube, point away from people, then stomp on the water bottle.
To reinflate the water bottle, blow down the stiff tube, before putting the rocket on again for relaunch.

Replace plastic bottle once this one stops working - try a bigger bottle (e.g. 2 litre), although stiffer plastics tend to crack sooner.

Add fins to the tube to make it fly straighter and higher.

Build with PVC tubing: https://www.youtube.com/watch?v=za_2uj1mbyw

Discussion in terms of molecules:
When the plastic bottle is stepped on, the air is pushed out of the bottle and into the tubing next to it, creating an area of high pressure (i.e. the molecules of air are closer together). This high pressure region moves along the flexible tube (molecules always move from high to low pressure areas), and into the stiff tube. When the high pressure molecules exit the stiff tube, they hit the cardboard rocket and push it upwards. The pressure is great enough to exert a force that sends the rocket high into the air.

Notes

Some water bottles are hard for younger students to reinflate, so are not recommended. For smaller bottles, I found the thinner plastic water bottles (500 ml) are easy to inflate and can send the rocket high. The slightly larger, thicker plastic bottles (about 700ml, water or soda drinks) are much harder to inflate. 2 litre bottles work fine but crack open sooner than the thinner more flexible plastic of the small bottles.

If the diameter of the

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6
Gr 7

Luminescent candy

Summary
Smash wintergreen lifesavers to show luminescence from mechanical cleavage (Triboluminescence). Same mechanism as lightening.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Physical Science: Chemistry (grade 7)
Materials
  • dark room e.g. behind curtains on the school stage
  • wintergreen lifesavers (must contain methyl salicylate)
  • hammer
  • dark cloth
  • clear piece of plexi, or other hard plastic
  • tray to contain flying lifesaver pieces
Procedure

This activity needs quite a dark area, so give students a while to get their eyes adjusted to the dark first.

Place a wintergreen lifesaver on the cloth under the piece of plexi.
Smash the plexi with a hammer.
As the candy gets broken into small pieces, flashes of blue light are seen in different places under the plexi.

Young student explanation: when you hit the candy you put in energy. The energy comes out again as light. It is lightening on a very small scale.

Older student explanation: As you hit the candy you separate charged particles. As electricity flows between them it excites the nitrogen in the air. The excited nitrogen re-emits the energy as light - mostly UV but some blue. This happens with regular sugar, but the light emitted is mostly UV so not so visible. This is the same chemistry as lightening. The wintergreen flavour amplifies the light - methyl salicylate is a fluorescent molecule: it absorbs the UV emitted by the nitrogen and re-emits blue light, so making the light given off more in the visible range where we can see it.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4

Fluorescent toys

Summary
Use a UV light to look at fluorescent pens, toys etc. Some rocks are also fluorescent.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Physical Science: Chemistry (grade 7)
Materials
  • darkened room e.g. behind the curtains on the school stage
  • UV light
  • fluorescent pens, toys
  • optional: fluorescent rock e.g. calcite
Procedure

When you shine light on these items they glow. The UV light gives fluorescent molecules extra energy. They release this energy again as light.
(Older students: discuss how electrons move to a different energy level when excited by the UV light, then release photons of a different colour light as they return to unexcited state).

Fluorescent markers only glow when the UV light hits them - the fluorescent molecules release the light energy right away.
Glow in the dark object release light after the UV light is taken away - the "phosphorescent" molecules in them release light slowly.

Some rocks are fluorescent. See photo of calcite fluorescing pink.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 5
Gr 7

Glow stick chemistry

Summary
Use glow sticks to make light, discuss the chemistry of how the light is made, and use temperature to change the rate of the reaction.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Physical Science: Chemistry (grade 7)
Materials
  • darkened room e.g. behind the curtains on the school stage
  • glow sticks, one per student
  • tub of iced water (about 5 centigrade)
  • tub of warm water, about 45 centigrade
  • thermometer
Procedure

Explain that inside the plastic of the light stick is a glass rod. One chemical is inside the glass rod and another is outside. When you snap the glass rod by bending the light stick, the chemicals mix together, and the chemical reaction produces a new molecule that glows.
Turn the lights out, then ask students to snap their sticks all together. Ask students to look closely as the chemicals mix - they should be able to see a swirl of colour as the chemicals react and new coloured glowing molecules are made.
First photo shows the chemicals mixing and making light.
(Older students: the tube contains hydrogen peroxide, which mixes with a chemical outside the tube. Two chemical reactions result in the dye getting excited as it gains energy. It releases this energy again as light. Additional dyes make the glow sticks different colours. See Wikipedia entry for more details).

Ask students to find out how heat and cold affect the rate of the chemical reaction in their light sticks, by dipping the light sticks in the warm and iced water tubs.
They should have found that in the warm water the light stick glows more intensely. This is because the heat energy causes the molecules in the light stick to move around faster, hence collide more often and chemically react to make more glowing molecules.
The light stick dipped in cold water should become dim. Heat energy leaves the lights stick and moves into the cold water, hence the molecules in the light stick have less energy and move around less. The cooler molecules collide less frequently, so undergo fewer chemical reactions to make glowing molecules.
(Sometimes students see something different, possibly due to the intensity of the glow stick affecting the sensitivity of our eyes in the darkness. These are real results as they are what the students found, but during discussion focus on what the majority of the students found.)

Students can make bright and dark stripes along their glowstick by dipping in one tub, then dipping it not as far into the second tub.

Discuss how the chemicals are used up when it glows brighter, and how they can preserve their glow sticks by putting them in the freezer overnight to slow the chemical reaction down.

Notes

Don't make the hot water too hot. It will melt the plastic and the stick will leak. I have read that 50 centigrade is as high as you should go. On using dollar store glow sticks, I used hot water, and a couple of them leaked. Maybe the low quality product, maybe the water too hot.

Glow sticks can become a lesson themselves with other activities. Persistence of vision demonstrated by taping string to a glow stick and spinning it around - we see a circle of light. ??isas noticed a gap in the circle of light - can you measure the processing time from this??

Run a glow stick lesson as play-debrief-play. Provide students with hot/cold water, string, darkness... discussion to learn about light from their discoveries. Maybe include a song by a nerdy science band on light, to dance to with the light sticks...

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5

Candle chemistry (wax combustion)

Summary
Watch a candle burn, put it out by removing air. Model the chemistry of what makes it burn, and relate to fossil fuels. Also relight a candle from above the wick.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Physical Science: Chemistry (grade 7)
Materials
  • candle in holder
  • lighter
  • vase, or other glass vessel that will fit over the candle and holder
  • optional: molecule models - one black carbon, 4 white hydrogens, 4 red oxygens and 8 grey bonds per set
Procedure

Students can draw the candle while it is burning, to notice the different colours of the flame, the liquid wax below the wick etc.

State changes in the wax:
Solid to liquid to gas. The solid wax melts with the heat of the flame, and the wick draws the liquid wax up by capillary action. Once the wax is a gas it can burn.

Energy transformations with a candle:
Chemical energy of the candle wax is converted to light energy and heat energy.

Chemical reaction of a burning candle:
Place a jam jar over the candle - it burns for a while then goes out.
The wax needs oxygen from the air to burn. Also note that water condensation builds up on the inside of the glass.
Place differently-sized jars over identical burning candles, to see that the candle with the larger jar will burn longer (as there is more air in it).

The molecules in the candle wax and oxygen from the air combine and rearrange, and release heat and light as they do so.
Optional: use molecule models to show a simple version of the chemical reaction: CH4 + 2O2 → CO2 + 2H2O. Called combustion. The reaction product water is visible on the glass.
(Paraffin wax is actually longer chains of C and H atoms, called alkanes, with average 25 carbons. So the chemical reaction would be C25H52 + 38 O2 → 25 CO2 + 26 H2O. The generic chemical formula of wax is: C(n) H(2n+2). The wax combines with more molecules of O2, to release the same products.)
Cover identical candles with differently-sized jars at the same time. Ask students to predict which one uses up oxygen first. (Students need to estimate the relative volumes of the jars.)

Candle trick:
Once the flame of a larger candle has been lit, it can be blown out, then relit from a height above the wick. The wax vapour still in the air ignites, which then relights the wick. The flame must be quite big for this to work.

Additional information on flames:
The flame is a mixture of hot gases, primarily CO2, water vapour, oxygen and nitrogen.
The yellow colour of the flame is due to soot particles glowing because they are hot (black body radiation). Other colours in the flame are from transient reaction intermediates during combustion such as the Methylidyne radical (CH) and Diatomic carbon (C2). These molecules are excited, then emit blue and green visible light (spectral band emission).
https://en.wikipedia.org/wiki/Flame
Try burning copper sulphate or other chemicals to make other flame colours.

For more detailed chemistry of a candle burning see the ChemMatters issue on candle chemistry: http://chicagoacs.net/statefair/CD-2008/Chemmatters/2007_12_smpissue.pdf

Notes

For a lesson on heat convection, only included covering candles with jars to show that they need air to burn.

Try the candle see saw.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6
Gr 7