ingridscience

Add a couple of drops of indicator dye to the water in the cup to measure the pH of the water. It should be around 7.
Add some carbon dioxide to the water from breath: either blow through a straw into the water, or blow into the tube and then shake the exhaled air into the water (repeat blowing into the tube and shaking as necessary), until the colour changes.
Read the new colour of the water on the pH chart - it will have dropped i.e. become more acidic, to about pH 6.

The acidification of the water is reversible: waft in fresh air and shake it into the water. This air has less CO2 than our breath, and slowly, as more air is wafted into the tube and shaken into the water, the pH of the water will return to neutral. It will take longer than acidifying the water in the first place.

Climate change and ocean acidification
The water in the tube absorbs the CO2 from your breath, just as the oceans absorb increased CO2 in the Earth's atmosphere. As the CO2 in the water increases, the pH of the water falls - it becomes more acidic.
As we increase the amount of CO2 in our atmosphere through emissions, we are acidifying our oceans.
A dramatic climate change and ocean acidification event happened during Earth's history, and is evident in ocean bed core samples.
The Paleocene-Eocene Thermal Maxiumum (PETM) was a major greenhouse warming event 55 million years ago, resulting from a massive carbon release into the atmosphere (likely methane as well as CO2) which acidified the oceans. Ocean bed core samples show that this increase in greenhouse gases led to a sudden decrease in shell deposits (e.g. https://www.ecord.org/website/wp-content/uploads/2016/02/replica208a.jpg Also image here or here) - the shells of ocean animals dissolved in the more acidic ocean water before reaching the ocean floor, and the core samples showed just red clay. The greenhouse gases we are currently releasing into the atmosphere are at a much greater rate than this previous greenhouse event, and will lead to a similar effect on ocean life. Life in the oceans is linked to all life on Earth, so if we affect ocean life by acidifying ocean water, there will be knock on effects to all life on Earth.
But, there is hope!
As the students waft fresh air into their tubes, the acidification of the water will reverse and it will return to pH 7.
This shows that ocean acidification is reversible. If we can lower our emissions to reduce the CO2 in the atmosphere, the oceans will recover.

Blood CO2 levels affect our brain and heart response
When you exert yourself you need more oxygen. You also release more CO2, which makes your blood more acidic. A part of the brain called the medulla oblongata measures the pH of the blood, so can determine how much CO2 is in the blood. Once the acidity gets to a certain level, the medulla oblongata signals your body to speed up breathing and to increase heart rate. Increased heart rate will increase O2 levels in the blood again and also remove the excess CO2 from the blood.
(You can use the cortex of your brain to override and slow down breathing by thinking about it.)

This activity is how to dissect the brain before a lesson.
Follow the description of the parts of the brain, and associated activities, in the brain lesson.

The brain will probably already be cut, with left and right sides separated.
If not, slice it in half.
Look at the parts: cortex, cerebellum, mid and hind brain, corpus callosum: see labelled image at www.biologycorner.com/anatomy/sheepbrain/brain_dissect07.jpg

Discuss the functions of the parts:
cortex: thinking, reasoning, also optic, motor and olfactory areas.
cerebellum: fine motor control
mid and hind brain: basic processes such as breathing, heart rate, sleeping, waking etc
(See the Nervous System lesson plan for more details)

The intact brain can be stored in the fridge for days if covered in saran wrap to prevent drying out.

To see more cut the brain with a sharp penknife.
Cut parallel to the cut already made separating the left and right halves, but more lateral, to reveal the striatum and possibly the hippocampus.
Cut through part of the cortex to show the white and grey matter (the myelinated axons and the pinkish cell bodies).

Great images of a sheep brain dissection at:
https://www.biologycorner.com/anatomy/sheepbrain/
More nice photos at:
www.exploratorium.edu/memory/braindissection

Rocks may be made up of one mineral, or a group of minerals whose crystals have grown together. To help identify a rock by the minerals in it, there are a variety of tests including test for hardness and streak colour.
1. Testing for hardness:
The Moh’s scale is a scale of relative minerals hardness from 1 (talc; very soft) to 10 (diamond; very hard). It is used to help categorise and identify minerals. The hardness of a mineral can be measured by how easily it is scratched, either by other minerals of known hardness or with calibrated tools.
Students use a steel butter knife blade (scratched by minerals more than 5 or 6) to test the hardness of minerals to help identify them (see attached example). Other common materials to test for hardness are: fingernail (2.5), copper penny (3-3.5), steel nail (5) , pocket knife (5.5), window glass (6), steel file (6.5).
2. Testing for streak colour:
The overall colour of a mineral may vary if it contains impurities or has an irregular crystal structure, whereas the powder of a mineral has a more consistent colour. Scraping a mineral across a “streak plate” (unglazed porcelain) produces a line of powdered mineral whose colour can help identify the mineral. (If the mineral is harder than the streak plate (~7 on Mohs’ scale) another crushing method must be used.)
Scrape the minerals across the porcelain to examine their streak colours and identify them (see attached example).

These tests can be used to investigate locally mined minerals and their products e.g. bornite is mined in BC for its copper content (native copper sources are rarer). Much copper is recycled.

Go on a beach walk to find granite, or bring it into the classroom. Students will have seen it frequently, but likely not have taken notice.
On Vancouver beaches, granite (an igneous rock made up of different minerals) is often in the form granodiorite (black granite), which is speckled black, white, and grey/pink. Other common Vancouver beach rocks: smooth black rocks are likely to be basalt (igneous rock, cooled lava), and flat rough light brown rocks are likely to be sandstone (sedimentary rock made up of different minerals). Smaller pieces of quartz (a mineral) may also be found - clear or yellowish and more shiny.

Younger students can sort granite from other rocks by its speckled appearance.
Students can draw the outline of their black granite, then choose one part of it to draw in detail. (A pencil is sufficient to show the blacks, greys and whites).

There are three minerals in black granite: mica, quartz and feldspar. They make up the patches of colour in the granite.
Ask students to name the colours they find, using their flashlights (and optionally magnifiers with older students, but note that rock will scratch any kind of magnifier). Then write up the colours, assembling them into the minerals they are likely to be:
black, gold, silver (mica)
white, grey-blue, purplish (quartz)
yellow, orange, pink, brown (feldspar)
Name the minerals for the students.

As they look further at their rocks, and try and find the largest crystals they can (the largest "grain size'), circulate with samples of black mica, quartz and feldspar. Students can shine their flashlights on the samples you bring to see their colour and shiny surfaces better.
Alternatively, display the minerals for the students to look at independently at a station (see photo).

More information on the minerals in granite:
Another form of mica is white.
Quartz can come in other colours and makes beautiful crystals - show amethyst if available.

(Optional: show other rocks where the minerals are distinguishable).

Discuss how the black granite was made.
The black granite we are holding was once deep inside the earth. It is so hot in there that the rocks have melted (called magma) and all the minerals are liquid (show picture of a cross section of the earth). Imagine how hot it needs to be to melt rocks! As magma slowly moves towards the surface again it cools down, and this granite was made when mica, feldspar and quartz organized into their individual crystals as they cooled.
Some magma comes to the surface fast, and erupts from volcanoes. Magma from volcanoes cools very fast to form igneous rock, but it has much smaller crystal grain sizes than igneous rock that cooled inside the earth. Show volcano rocks - basalt (common here), pumice and obsidian. Can see gas bubbles in them.

Students model what happens to sugar molecules as yeast eats them.

Give each student/student group a sugar molecule (C6H12O6).
Tell them that one of the products as yeast breaks glucose apart is ethanol, and show them how to build it (CH3CH2OH). They should make two ethanol molecules.
Ask them to make two identical molecules with the atoms that remain. (Two CO2 molecules). It might be a challenge to figure out that there are two double bonds in CO2.

Once they have all made the CO2 molecules, spell out the name while pointing at the atoms "C-O-2", and some students may recognize the name and know it is carbon dioxide.
Ask what state of matter CO2 is (gas), and ask what might happen if this gas is stuck in bread dough (it will make it rise).