ingridscience

For a free play activity using found objects:
One student adds an item to the tub e.g. pine cone, leaf etc. and snaps on the lid.
Their partner tries to guess what is in the tub, by shaking it and hearing the sounds made.

For a structured activity set up by the teacher:
Before the lesson, tape different items into shoe boxes, and leave one shoe box empty. I used metal cups in one, a ball of cloth in another, and rice in another.
Add a metal ball to each box. Seal the boxes. Make sure all holes are blocked, especially for a box containing rice grains.
Ask students to tip the boxes, and deduce what is inside from the sounds they hear.

Discussion on how scientists use sound to learn about the sun:
Scientists listen to the sounds coming from the inside of the sun, to learn about its interior structure. (Called "helioseismology".)
The Sun's sound waves bounce from one side of the Sun to the other in about two hours, causing the Sun's surface to oscillate, or wiggle up and down. Because these sound waves travel underneath the Sun's surface, they are influenced by conditions inside the Sun. So scientists can listen to the sun to learn more about how the structure of the Sun's interior shapes its surface.
The Sun's sound waves are normally at frequencies too low for the human ear to hear. To be able to hear them, the scientists sped up the waves 42,000 times, and compressed 40 days of vibrations into a few seconds.
What you hear in this audio track are just a few dozen of the 10 million resonances echoing inside the Sun:
http://solar-center.stanford.edu/singing/SOUNDS/three_modes_l_0_1_2.mp3

Review states of matter that the students know: often just solid, liquid and gas.
Review the spacing of the atoms/molecules in each state of matter (close in solids, further apart and free to move in liquids, even further apart and even more energetic in gases) and that in each state the particles are progressively more energetic.
Tell students that when gas is energized even more, the atoms split apart and the electrons become free from the nuclei. This is a 4th state of matter, called plasma.

In the plasma ball, plasma is produced when electrons moving at high speed (from the central electrode to the glass of the ball) bump into gas atoms and break them apart.

In the sun, the extremely high temperatures and pressure split the atoms to make plasma.

For classes where this activity is not to take up too much time, the teacher can demonstrate by holding the balloon/foam ball and walking around the circle.
The activity can be simplified as needed for any K-7 classroom.
The critical idea is that with the Earth's tilt, as it moves around the sun, either the Northern or the Southern hemisphere gets more or less direct light shining on it, so creating the seasons.

Blow up a balloon for each student, only half inflating it, so that it is as round as possible.
Give each student a balloon to represent earth.
Ask students to hold the balloon with the tied neck at the bottom, then to draw on the equator with a sharpie.
Then draw on a rough outline of North America, using a globe or map as a guide. Add a dot for Vancouver.
Keen students can add other places that they know/are from.
(See notes and second photo for using a foam ball on a skewer instead.)

Place the light fixture in the centre of the room, on a desk/chair so that the bulb is near head-height for standing students.
Ask the students to make a circle around the light fixture, large enough so they have good elbow room between them.
Darken the room.

Ask students to point the North Pole of their "earth" balloons towards a high feature in the room e.g. a corner. The designated feature of the room is the "Pole Star" or "North Star". With the North Pole towards the Pole Star, each earth should be tilted, ideally at an angle close to the real tilt of the earth (24 degrees from the vertical).

Ask students to position their earth in front of their bodies so that the "sun" is shining on the earth, while maintaining the tilt towards the Pole Star.
Ask students which is east and west on their earth. If they look at the continent of North America, it should help them.
Ask students to rotate the earth in the correct direction: the sun rises in the east, so the light of the bulb should hit the east coast of North America first. They will be rotating their earths counterclockwise.
For the real earth, each rotation takes one day. As the sun hits our continent it is day time and as we continue to rotate it becomes night time.

Now, we will show what happens during the year, as the Earth orbits the Sun once.
Ask students to walk in a circle around the "sun", always tilting their North Pole towards the Pole Star, while continually rotating their earth counterclockwise (as viewed from above).
Once they have walked completely around the sun and ended up back where they started, a year has passed.
Now walk through another year while asking students to keep an eye on how much sun Vancouver on their Earth receives through the year.
Ask where in the circle does Vancouver get the most time in the sun? (The northern hemisphere will be tilted towards the sun at this position in the circle.) This is the position of midsummer - the summer solstice. Mark this place in the circle with "June" (on the floor, or on the wall behind the circle).
Ask where in the circle does Vancouver get the least sun exposure? (The northern hemisphere will be tipped away from the sun at this position in the circle.)
This is midwinter, or the winter solstice. Mark this position with "December". It should be exactly across the circle from June.

(Optional:
Add that the vernal (spring) and autumnal equinoxes fall between, in March and September.
Students can locate where their birthday month falls in the circle.)

Now ask students to orbit the sun once more, with their tilted, rotating earths, and watch what happens to the north and south poles.
Each of them get sun all day for part of the year.
The sun never sets in Northern Canada in the summer as it is so close to the North Pole.

(Optional:
Discuss seasons in the northern and southern hemispheres, especially if a child in the class is from the southern hemisphere.
In the northern hemisphere, mid summer is in June, whereas in the southern hemisphere, midsummer is in December.)

To review:
In our summer, the northern hemisphere is tilted toward the sun, so has more hours of sunlight through the day (as shown by the above activity). More hours of sun exposure makes it warmer. See this image to review this point: http://www.srh.noaa.gov/srh/jetstream/global/images/seasons.jpg
In addition, the hemisphere that is tilted toward the sun also receives more direct rays of sunlight (or rays that are closer to perpendicular or a 90° angle), which means more intense radiation, so more heat. See this image to show clearly: http://astro.hopkinsschools.org/course_documents/earth_moon/earth/seaso… (backup image: http://web.gccaz.edu/~lnewman/gph111/topic_units/Earth_Sun/01_23.jpg)
The combination of more direct rays of sunlight and more hours of daylight causes the hemisphere that is tilted toward the sun to receive more solar radiation and to have warmer temperatures.

Please note:
A common misconception is that our seasons are caused by the distance from the sun. This is not the case. Our seasons are caused by the the hours of sunlight, and the angle of the sun's rays, as described above.

The surface of the moon is covered in moon regolith (moon dust), a few metre to tens of metres deep. image at https://en.wikipedia.org/wiki/Regolith#/media/File:Apollo_11_bootprint…
Earth regolith is formed by erosion - the wind and rain brush tiny particles from rock and erodes them.
Moon has no running water and no wind - how is the regolith formed? By the impacts of meteorites.

Simulate the formation of moon regolith by banging one rock (the surface of the moon) with another rock (a meteorite).
A fine dust is formed. Collect the dust in the tray with the white lining.

To look at a property of the regolith, lay the plexi sheet over the tray of regolith, and rub a hand over it.
Students will find that the regolith jumps up to the plastic, and dances up and down, and they can spend a while experimenting. If they cannot get the dust to jump, try using a drier (non-sweaty) hand and rubbing faster (a piece of cloth may also help).
The regolith jumps because of electrostatic charges. Rubbing the plexi sheet gives it a charge, which attracts the tiny grains of regolith that are also charged.

Moon regolith is even finer (1/100 mm) than the dust made here, and also more charged (because it is bombarded by charged particles from space). When we land on the moon, the dust coats space suits, solar panels and camera lenses. (See image at http://www.space.com/18907-schmitt-covered-with-lunar-dirt.html
_GPN-2000-001124.jpg). Moon regolith is also sharp enough to wear away space suits and scratch visors. (Image of regolith magnified at https://media1.britannica.com/eb-media/30/76830-004-38A20966.jpg)
Technology has overcome some of these challenges, for example electric fields are wired on camera lenses and surfaces to attract the moon dust to the side of the lenses.

To do the activity with a camping stove:
Push the straightened paper clip into the cork, to make a flame test tool.
Dip the wire in water, then in salt, then put it in the flame. The flame should be yellow.
Burn everything off the wire.
Dip the wire in water, then in copper sulphate if available, then put in the flame. The flame should be blue/green.
Potassium chloride, in large enough amounts of powder in the flame, burns purple.

To do the activity with a campfire:
Throw copper sulphate into the fire, to make green-blue flames.
Boric acid crystals make green flames.

The colours appear when electrons in the metals, excited by the heat, fall back to lower energy states and release light.
Fire can be different colours depending on what is burning.

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.