ingridscience

Use a strip of paper to make a mobius strip: hold the strip flat, twist one end one half turn, then tape the ends together.
How many sides does it have?
Use a pencil to draw a line down the middle of the strip, and find out that the strip has just one side.

Make other mobius strips with different number of twists and find out how many sides they have.
Record the results to find the mathematical pattern: an even number of twists gives two sides, an odd number gives one.
(See attached worksheet).

Play around with cutting mobius strips down the middle to make new loops.
Play around with joining strips together, then cutting them both down the middle (see images).

We are going to make some butter to put on the bread that is baking, and we’ll look at the molecules in that process.

Butter is made from cream. Cream has many different molecules in it, including the three in your collection. Recognize any of them?
[Water, fat and phospholipid.]

We know that fat and water don’t like to mix. Show students a tube of water, then pour in oil, and watch them separate into layers.
At the molecular level, the long tails of the fat molecules (made up of carbon and hydrogen) don’t want to be near the water molecules. (It’s because one of them has a charge [water] and one does not [fat].)

But in cream the water and fat molecules are able to mix together. Drops of fat in the water are stabilized by phospholipid molecules.
The long tails of carbon and hydrogen like to touch the fat molecules. The head has lots of red oxygen molecules, and you might also see a purple phosphorus and a blue nitrogen in there - this end of the molecule can touch water molecules.

Arrange your fat molecules into drops. Surround them with water molecules. Then add the phospholipid molecules so that they make a barrier between the fat and the water molecules, oriented so that all the molecules are stable.

You have made an emulsion, which is what cream is. Drops of liquid fat suspended in water.
This is what is in the jar of cream sitting on your desk.

In a moment we will shake the jar of cream - the emulsion drops are shaken apart and the component molecules come together with molecules they like to be with [that look like themselves]. Do the same with your molecular model.

The fat molecules join together in one big group as butter. The water separates in another group as buttermilk.
The phospholipid molecules can be part of the buttermilk as their own group, or they can surround a couple of water droplets trapped within the fat molecules (butter does have some water in it).

Now you can shake your cream to break open the fat droplets and form two separate fat and water groups: butter and buttermilk. Keep shaking until you have these two separate entities in your jar - the solid butter fat and the white liquid buttermilk.

Set up the binoculars as in the first image, with once eyepiece poking through the cereal box.
Stand them on the tripod about 1m away from the board.
Adjust the angle of the binoculars so that the sun's image is projected on the board, then focus so that it is clear.
If you are lucky you will see dark spots on the face of the sun.
Check http://www.tesis.lebedev.ru/en/active_areas.html to find out what you should be looking for.

Sunspots are caused by strong magnetic fields that block heat coming from the inside of the sun, which allows the region above to cool (to 3700°C). They have a darker core, "umbra", surrounded by a lighter "penumbra" and are often larger than the Earth.

They move across the surface of the visible side of the sun as the sun rotates (about once every 2 weeks/month?).
By the time that area of the sun has come around again, the sunspot activity has changed.

Before cracking the egg, look at the shape of the egg, and show that as it rolls its shape makes it move in a circle. This means that eggs laid by birds do not roll off ledges.

Crack an egg at each table group.
Students draw the parts that they can see (maybe inside the outline of a shell, if the students are old enough to translate to the new shape).
Possibly use as an art project (see above water colour painting).

Students tell the class what they find, and together figure out/learn what the parts are for:
Yolk: Feeds the embryo. Protein, some fat, vitamins and minerals. (Iron, vit A, vit D, phosphorus, calcium, thiamine, and riboflavin.) Also lecithin, an effective emulsifier. Yellow like carrots.
Egg white: albumen, the Latin word for “white.” 40 different proteins. Layers of albumen protect the yolk and holds it in place. Also provides protein and nutrients for a growing embryo.
Chalazae: ropes of egg white. Hold the yolk in the center of the egg, so that the embryo can grow properly.
Eggshell: calcium carbonate. Air and moisture can pass through its pores. The shell also has a thin outermost coating called the bloom or cuticle that helps keep out bacteria and dust.
Membranes: between the eggshell and egg white. Defence against bacteria. Strong: made partly of keratin, a protein that’s also in human hair.
Air pocket: forms when the contents of the egg cool and contract after the egg is laid. (The small crater you see at the bottom of a hard-boiled egg is the imprint of the air cell.) Provide a pocket of oxygen for a growing chick.

More details on egg structure and function, as well as how these structures are nutritionally at https://www.saudereggs.com/blog/the-different-parts-of-an-egg/

Nicely detailed, but clear animation of a chick developing inside an egg: https://www.youtube.com/watch?v=PedajVADLGw&t=12s

Indoors, sit the students in a circle around the chicken cage. Outdoors, allow students to interact with the chickens.
Cover topics as appropriate for the students' age.
Compare to humans often.

Discussion topics around chicken adaptations:
Chickens are birds - they have two legs and two wings. Chickens cannot fly but if startled will flap into the air briefly.
Chickens have excellent eyesight (birds have the best eyesight of all vertebrates). Although their eyes are on the side of their head, they can very accurately peck at food.
Their beaks are adapted for how they eat. Other birds have differently shaped beaks adapted to how they feed.
Chickens lay eggs for us to eat. The eggs she lays, are not fertilized as we don't have a rooster. (Human females also have eggs.)
Birds feathers keep in heat and enable flight.
All birds have light bones (often partially hollow) so that they are light.
Chickens are the living ancestors of dinosaurs.

Chicken behaviour activity for older students:
Ask students to design experiments to test what foods each chicken likes, which chicken has the best eyes, which chicken can jump the highest etc. Bring in some rigor on experiment design, and assessing variables.

Hang the ruler/paint stick/popsicle stick over the edge of the desk.
Push it downwards, then let go, so that the ruler vibrates and makes a sound.

1. Change how much of the ruler is hanging over the edge of the desk and experiment with the different notes that are made. The "pitch" is how high or low the note is. A longer ruler hanging over the edge makes a lower pitch; a shorter ruler gives a higher pitch.
Note that the longest ruler may not make much of a note except the slapping against the desk, and the shortest ruler will not make a note at all, so work in the middle of the ruler. It also helps to start with a longer ruler, twang it, then make the ruler shorter while it is still vibrating. Then it is easier to hear the note rising in pitch as the ruler is moved.

2. Observe the vibrations of the ruler closely to correlate the frequency (speed) of the vibrations with the pitch of the note.
A longer ruler vibrates more slowly, so has a lower frequency. A shorter ruler vibrates more quickly so has a higher frequency.
Note that it is hard to see the vibrations as they get very fast when the ruler is very short, so start with the longer ruler and move it gradually slower.
This video shows the vibrations in slow motion: https://m.youtube.com/watch?v=4SpSwTvbZI4

Worksheet attached below for older students.

Discuss how the sound is made and why the pitch changes:
The vibrating ruler pushes the molecules in the air, making them bunch together. As the ruler vibrates back and forth it makes waves of molecules pushed together (pressure waves). The molecules transmit these pressure waves through the air into our ear, where they are converted to electrical signals that get sent to our brain.
When the ruler is longer it vibrates more slowly, so pushes molecules together less often, so the waves of molecules are further apart - the frequency of sound waves are lower. Lower frequency waves have a lower pitch.
When the ruler is shorter it vibrates more quickly, so makes higher frequency pressure waves, which have a higher pitch.

Making music with a ruler on a desk: https://www.youtube.com/watch?v=3qPzsoQzo9s