Ischoklad

Continuing with our study of how different materials are suited for different purposes, grade 3 made ischoklad. This is a mixture of chocolate which we all know tastes delicious with coconut oil which has a lower melting point than chocolate. We labeled a thermometer with different melting points. Then we melted chocolate with coconut oil. Students were very careful using candles. 

Using simple scientific equipment.

You can make ischoklad at home. It is really quite easy:

1. Melt 50 grams coconut oil and 100 grams chocolate. You can do this in a pan on the stove or in the microwave. Be careful not to overheat. 
2. Pour into forms.
3. Refrigerate until firm.

These will melt smoothly in your mouth because the melting point of coconut is lower than the chocolate and much lower than your mouth temperature. 

Body temperature 37ºC

Melting temperature of chocolate about 34ºC

Melting point of coconut oil 24ºC

The relates to the learning goal:

2.31 Be able to compare common materials and objects according to their properties 

In this case the property we discussed was melting point.

Shake it grade 4!

Last week students learned about yeast and its role in baking bread. This week we made butter. We reviewed compounds and mixtures and talked about how milk and cream were special mixtures called colloids. The fat in milk is in such small globules that it stays mixed unlike oil and water which separate. We shook some cream until it first turned into whipped cream. We had incorporated some air into the mixture. We kept shaking until the fat was clumped together and we had butter. This was a surprising experience for students. I hope some of them will try it at home. 

Warning for some extreme action shots. We were shaking like crazy!

Look at those muscles!

Keep shaking! 

My biggest joy was seeing how pleased these kids were with their cream and butter. 

More Shoots

Some students in grade 5 had some very determined seeds. They germinated under all sorts of conditions. Students collaborated and made some posters about germination. This gave them a chance to discuss their results with each other.  

We talked about how plants can bend and twist to lean toward or away from stimulus.  

Student's drawing with her bean. Here you can see most of the parts of a plant in mini version. 

We discussed transpiration. Putting celery, cabbage or carnations in colored water is a good way to see transpiration in action. The colored water moves up the plant. As the water evaporates, the color is left behind. 

Colony Collapse Disorder

Grade 7 has  been learning about classification of organisms. This lead us to a lot of activities about plants and animals and how they are classified. We have learned about seed dispersal and plant pollination. Bees are very important to pollination. We recently watched a film about Colony Collapse Disorder. Here is a link to that film. While we watched the film we enjoyed some local honey from Västerhaninge just south of Stockholm. Students are going to write about Colony Collapse Disorder (CCD). The criteria they will be assessed on is criteria D: Reflecting on the impact of science. In this assignment students will dicuss the causes of CCD and ways to prevent it. They should also discuss how our scientific progress sometimes causes problems. For this assignment I want students to post their work on a blog or website they are creating. They will use their blogs for future assignments. 

I have posted more about this assignment on my other blog about the impact of science. The Impact of Science. 

Craters on the Moon Grade 6

The Statement of Inquiry for our Solar System Unit is: Scientists observe patterns and use them to construct systems that explain how the solar system works.

One pattern students investigated and recorded was the size or craters created in a simulated lunar surface depending on different factors. Students were allowed to choose the independent variable; mass, size of their meteorite or height. The measured either the size of the crater or the size of the ejecta rays created by the surface being thrown out of the crater upon impact. We were able to see correlations and make conclusions about our predictions. 

Can you see the ejecta rays? We used cocoa on flour to provide contrast. 

Here is an interesting story about a real lunar meteorite.

http://www.theguardian.com/science/2014/feb/24/meteorite-moon-largest-lunar-impact-recorded 

For this task students were assessed on Criteria B: Inquiring and Designing and Criteria C: Processing and Evaluating.

It's important to make a lot of measurements.

Roots and Shoots

In grade 5 we are investigating Roots, Shoots and Fruits. We tasted some sunflower seeds and sunflower sprouts. I even made the students taste beet root. I should have taken a photo of that. Students designed an investigation about seed germinating. They were allowed to choose the seed and the conditions but they could only change one factor. (Fair Test). Students recorded their observations in a booklet. They were quite excited to see their seeds germinate. It is so amazing to see life emerge from a seed. Next we will study plant genetics and Gregor Mendel. 

Chick peas germinated in salt water and soapy water.

alfalfa sprouts

This years Google Science Fair winners investigated germination. Watch their video here.

Chick pea vs. Bean

Some of the learning objectives for this unit are:

Children will:

3.2 Be able to conduct scientific investigations

• Posing scientific questions

• Choosing an appropriate  way to investigate a scientific issue

• Using their scientific knowledge and understanding to predict the outcome

• Relating the outcome to their original prediction

• Making systematic and accurate measurements from their observations

• Drawing conclusions based on the evidence

• Explaining and justifying their predictions, investigations, findings and conclusions

• Recording and communicating their findings accurately using the most appropriate medium and the appropriate scientific vocabulary and conventions

• Repeating investigations, observations and measurements to check their accuracy and validity

• Identifying patterns in the results

• Using scientific language to explain any differences found in the results of investigations

• Suggesting ways in which their investigations and working methods could be improved

• Relating their own investigations to wider scientific ideas

3.5    Understand the importance of using evidence to test scientific ideas

3.29  Know about the effects of seed dispersal

3.30  Know about the conditions needed for germination

Class Pets

We have some new pets in room 32; worms! Some third graders ripped up newspaper for our worm box and we added some earthworms. We will feed them food scraps and see what kind of soil they can produce. Worms are lovely pets, they don't make any noise and they don't need to be taken out for walks. On the downside, you can't really cuddle with them.