ingridscience

Water pH test

Summary
Use a pH test to find out whether different kinds of water are acidic, basic or neutral.
Science topic (2005 curriculum connection)
Physical Science: Chemistry (grade 7)
Materials
  • water from different sources: seawater, drinking water, pond or fish tank water
  • pH test kit that can distinguish between pH 6, 7 and 8
Procedure

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.

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

Feather study

Summary
Look closely at feathers to understand how they are made. Sort feathers into types.
Science topic (2005 curriculum connection)
Life Science: Needs of Living Things (grade 1)
Life Science: Animal Growth and Changes (grade 2)
Materials
  • feathers of different types (wing, body, tail, down)
  • magnifiers and/or microscope
  • drawing materials and paper
    Procedure

    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.

    Grades taught
    Gr 1
    Gr 4

    Egg into bottle

    Summary
    Use gas pressure to pull a hard boiled egg into a bottle.
    Science topic (2005 curriculum connection)
    Physical Science: Force and Motion (grade 1)
    Materials
    • hard boiled egg
    • glass bottle
    • lighter and small piece of paper
    Procedure

    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.

    Grades taught
    Gr 4

    Chickens, eggs and feathers

    Summary
    Look at live chickens, then their eggs and feathers.
    Curriculum connection (2005 science topic)
    Life Science: Needs of Living Things (grade 1)
    Life Science: Animal Growth and Changes (grade 2)
    Procedure

    Do the chicken observation to get students talking about them and discussing their features. Frame in terms of adaptations
    Discuss why we keep chickens - for their eggs.
    Discuss what chickens eat. Feed chickens (dig them worms if possible).

    Do egg structure study.
    Discuss why the eggs are not fertilized - as there is no rooster. Remind students that humans make eggs too.

    Optional: weigh a chicken
    Weigh a person holding a chicken, then weigh the person alone. Students figure out to do subtraction to find the weight of the chicken.

    Do the feather study.

    With extra time end with fun activities involving eggs:
    Egg in the bottle activity.
    Egg drop challenge. (Use any materials to wrap an egg so that it does not crack when dropped from a height.)

    Grades taught
    Gr 4

    Air pressure rocket (demonstration)

    Summary
    Make a rocket powered by air pressure. This is a powerful rocket and requires strict supervision.
    Science topic (2005 curriculum connection)
    Physical Science: Force and Motion (grade 1)
    Materials
    • 2 litre soda bottle
    • support sticks and duct tape, better a stand
    • cork, drilled to hold ball pump needle, plus some hollowing out to allow air contact all the way through

    • bike pump with ball pump needle
    • water
    Procedure

    Prepare the rocket by drilling through the cork.

    Add water to the rocket, insert the cork containing the needle attached to the pump.
    Put it in the stand/stand upright.
    Ask everyone to stand well back, as it will take off with no warning at high speed.
    Pump air into the rocket until it takes off.

    The pressure of air in the bottle above the water increases until it is too high to be held in by the cork.
    As the cork flies out, the water flies out too, helping project the rocket higher.

    Experiment with amount of water for the best flight.
    Too much water means there is too much weight. Too little means there is not so much water shooting out to project the rocket higher.

    Lots of great explanation, plus how to construct on the Naked Scientists website: http://www.thenakedscientists.com/HTML/experiments/exp/water-rockets/

    Notes

    I made a stable stand from a plant pot.

    Grades taught
    Gr 4

    Rockets

    Summary
    Shoot off rockets powered by gas pressure, generated by various means.
    Curriculum connection (2005 science topic)
    Physical Science: Force and Motion (grade 1)
    Procedure

    Choose two activities for a lesson.

    Shoot off film canister rockets.
    Discuss the chemistry and the gas pressure that builds up and sends it upwards.
    Set off the more powerful baking soda and vinegar rocket as a demonstration, which uses the same mechanism.

    Instead of making the gas pressure from a chemical reaction, a chamber can be compressed to increase gas pressure: air pressure rocket (very powerful - be careful) or stomp rocket.

    Discover chemistry that makes real rockets fly.

    Energy transformations in rockets.
    Baking soda and vinegar/Alka seltzer rockets use chemical energy into motion energy.

    Grades taught
    Gr 4

    Combustion of ethanol in a jug

    Summary
    Burn ethanol in a jug to make a blue flame and a sound.
    Science topic (2005 curriculum connection)
    Physical Science: Light and Sound (grade 4)
    Physical Science: Chemistry (grade 7)
    Materials
    • large heat proof flask or jug
    • 95% ethanol
    • long handled lighter
    • safety goggles and a good distance between the activity and students
    Procedure

    Add a little ethanol to the jug.
    Swirl it around to coat the sides and evaporate into the volume of the flask.
    Ignite at the top.

    Discuss the chemistry of the reaction:
    ethanol + oxygen -> water and CO2
    Model the chemistry of the combustion reaction

    Grades taught
    Gr 4
    Gr 5

    Combustion of a ping pong ball

    Summary
    Light a ping pong ball on fire, and discuss the chemistry.
    Science topic (2005 curriculum connection)
    Physical Science: Chemistry (grade 7)
    Materials
    • ping pong ball
    • lighter
    • heat proof tray
    • outdoors
    Procedure

    Light the ping pong ball and watch it burn.

    The ping pong ball is fuel for a combustion reaction: it combines with oxygen to release heat and light. Carbon dioxide and water are made, along with an ash.

    Once the combustion reaction starts, the heat it generates keeps the reaction going.

    Grades taught
    Gr 4

    Molecular modelling of combustion of ethanol

    Summary
    Use molecule models to figure out the chemical reaction of combustion.
    Science topic (2005 curriculum connection)
    Physical Science: Chemistry (grade 7)
    Materials
      molecule pieces for combustion of ethanol:
    • ethanol molecule: two black carbons, one red oxygen, six white hydrogens, eight grey bonds
    • three oxygen molecules: each two red oxygens, 2 grey bonds
    • molecule pieces for combustion of hydrocarbon:

    • methane molecule: one black carbon, four white hydrogens, four grey bonds
    • two oxygen molecules: each two red oxygens, 2 grey bonds
    Procedure

    Either build the starting molecules, or ask students to make them: one ethanol molecule and three oxygen molecules.

    Tell/remind students that ethanol is a fuel that burns in oxygen, and that when the fuel and oxygen chemically react their atoms come apart and recombine into new molecules.
    One of those new molecules is water (H2O), and it makes three of them.
    Ask students to pull apart their ethanol and oxygen molecules, and rearrange them to make three water molecules.
    Then tell them that the remaining atoms and bonds make the other reaction product. There are two identical molecules of this second product.
    Give them time to use up all the remaining atoms and bonds to make two identical molecules. With time, they should arrive at CO2, or carbon dioxide.

    So when ethanol (or other fuels) burn in oxygen the reaction products are water and carbon dioxide.
    Sometimes carbon (as soot) is also made, when not all the carbon combines with oxygen (called incomplete combustion).

    Additional information on the flames that are often present during combustion:
    The flame is a mixture of hot gases, primarily CO2, water vapour, oxygen and nitrogen (nitrogen comes from other materials that burn).
    Energy in the flame excites the electrons in some of the transient reaction intermediates such as the Methylidyne radical (CH) and Diatomic carbon (C2), which results in the emission of visible light (blue and green for these radicals) as these substances release their excess energy.
    https://en.wikipedia.org/wiki/Flame

    Grades taught
    Gr 4

    Combustion

    Summary
    Do a series of activities involving combustion - a chemical reaction with oxygen that gives off heat.
    Curriculum connection (2005 science topic)
    Physical Science: Chemistry (grade 7)
    Procedure

    Define combustion: when a fuel reacts with oxygen, giving off heat.
    A source of heat is needed to initiate combustion, and once it has started, it self sustains from the heat it produces.

    Do the candle activity, or the jug, or both.

    Using molecule models, students figure out the products of combustion.
    With the candle and the jug, water condensate is found around the reaction site.

    Candle see saw for more candle activities.

    Optional: challenge students to light a campfire - what do they need? Fuel (paper then wood), oxygen (fire built properly to pull oxygen through it) and heat (lighter to start it).
    Do flame colours in the campfire with copper sulphate, or on a camp stove.

    Add other activities if time, reminding students that the fuel (whether candle wax, firewood, ping pong ball plastic or ethanol) reacts with oxygen to release carbon dioxide and water.

    Grades taught
    Gr 4
    Gr 5