New Find: Corrosion Demo

Corrosion Demos This page has an amazing demonstration for corrosion, incredibly visual and fast to show in a classroom setting. This is a very good way to show corrosion actively happening rather than the usual nails in large conical flasks (which does look impressive over time, but not on the short term). Showing corrosion with nails in a flask also tends to ruin some of the glassware so can be pretty wasteful, petri dishes are supposed to be disposable! The link also includes the student sheet and slides for teaching with.

I can’t wait to try this one!

E is for Explore!: Red Bull and Milk Reaction

E is for Explore!: Red Bull and Milk Reaction.

What happens when you add Red Bull to milk in a 1:1 ratio?

What about vinegar and milk in the same ratio?

Change the type of milk from whole, to semi, to skimmed!

Why does any of this happen?

This simple, quick and clean demonstration is perfect for an introduction to States of Matter, to get brains thinking on an Open Evening or as a mini experiment for a STEM session.

Definitely one to try out! And easily performed and explained at home.

Biodomes Engineering Design Project: Lessons 2-6 – Activity – www.TeachEngineering.org

Biodomes Engineering Design Project: Lessons 2-6 – Activity – www.TeachEngineering.org.

This is a fantastic resource for designing a bio-dome, excellent for studying ecosystems, specific environments and engineering (there’s also a nice little bit of recycling of plastic bottles involved). The webpage also details how to approach a number of lessons teaching with regards to the bio-dome that students can build. There is also a Bio-dome workbook in pdf that can be downloaded from the page, a full list of materials needed, an introduction with extra vocab section and a simple to use instruction on how to build a simple model bio-dome.

The lesson plans given by Teach Engineering break down different things to look at/study within the bio-dome (energy flow, plants, animals and then decomposers), these could easily be adapted to fit what a teacher specifically wanted or to fit different timescales, you wouldn’t need to add plants, animals and decomposers over 3 weeks unless it helps to establish each one first. Maybe that’s what a school technician is for, hehe!

I think it would be fascinating for a class (or STEM group) to do this over perhaps a few weeks with maybe one built bio-dome for everyone, to see the effects of the bio-dome. The website recommends roughly 5 hours of “lesson” time, but however much of it could be done outside of a lesson to speed learning up.

STEM – Blackcurrant Osmosis

Who doesn’t love Ribena? And chips? Okay, maybe not really together as such. I found this experiment through Practical Biology a few years ago, but have only just got around to testing it myself and then putting it into a STEM session. The Practical Biology/Nuffield site have lots of different experiments you can browse through, each with teacher and separate student guidance. I simplified the Blackcurrant Osmosis one for the time and age of the students.

It really is very simple and easy to set up. Also, it’s very visual for students to look at. Here are some of our potato chips after 15-20 minutes in different Ribena concentrations –

Blackcurrant Potatoes

It’s quite obvious which one is 0% Blackcurrant and which is 100%. It’s pretty clear even for the other concentrations. That wouldn’t happen with plain old sugar water, would it?

We did this with a group or KS3 who knew nothing about osmosis, nothing about concentration and had never done a practical quite like this before, but in the hour session they all did pretty well. I think this would be perfectly suited for an hour length lesson especially with the right background knowledge. I would simplify it for a repeat STEM session though and cut all of the chips to perfect size so that step could be cut out completely. I am pretty amazed at how well the year 7s did with making the different concentrations and, from the results, all of the concentrations were made pretty accurately. There was only one group with anomalous results that made no sense!

0% - 80% Strength

It’s all actually quite simple really – make 6 concentrations of blackcurrant squash (from 0% to 100%) (oh, and whilst Ribena works very well, so does the blackcurrant cordial we tried), put a pre-weighed potato chip into each concentration and leave for 15-20 minutes.

Floating Chips

(Note how the chips float with increasing squash concentration. Can you explain that?)

Then, remove each chip, pat them dry and weigh each one again. Then calculate the percentage change in mass.

0% - 100% Chips

The 0% blackcurrant was the only chip to not lose mass as water moved into it from the greater concentration outside of the potato cells. All of the others had water leave the chip via osmosis (to varying extents) as the water concentration was greater within the chips compared to the sugary Ribena.

For younger students, if you leave the chips in long enough they might get enough out of the experiment from just seeing the purple coloured chips. Can they explain it? And then with age/knowledge move on to the theory behind osmosis and the graphing example Nuffield gives.

I’d also like to try their example of altering this experiment to show the rate of water movement. Perhaps that would be better for understanding the basics behind osmosis for younger students.

British Science Week – Activity Packs

From 13th to 22nd March, it is British Science Week and a page of Activity Packs has been produced by the British Science Association, linking to 15 short activities, arranged by age that can be done to celebrate British Science Week.

There is also a flyer that can be printed, and a collection of curriculum links that apply to the under 11 and 11 – 16 year old activities.

Some of the activities included are building a giant egg timer (prepare in advance with multiple 2 litre plastic bottles!), battery building (not too different to the fruit battery testing that our own STEM group did), wireless signal blockade (handy if you have the right equipment and are allowed to use your phone in a classroom), metallic food (separation techniques, magnetism and easy to do at home as a nice food comparison), and many others.

I think it would be nice to give a class or STEM group their choice over which practical they’d like to do and to work their way through a selection of them. That’s why I’m going to post this earlier than British Science Week – to get you ready and prepared!

I might also keep this list handy to try some at home in a few years!

Food Preservation and Microbial Growth – Spices!

I got sent the following link to have a look into for our KS4 and possibly STEM groups – Antimicrobial Properties of Spices – and it looks really interesting, although I am biased as Microbiology is my background. The journal article is very well laid out and planned, easily adaptable to use in a classroom setting or even for some at home science and the scientific explanations are not too difficult to get your head around. Some rice pudding and different spices… that’s all you really need and you’re off. You could use any spices that you want, powdered and out of date samples like the paper uses, too.

I then did a very quick google search and found this link – Ability of Curry and Cinnamon to Inhibit Bacterial Growth – and loved the even greater simplicity. This method would be perfect for our STEM sessions. I do prefer microbiology experiments to be performed on actual agar (I think it makes it safer for the students as they are consciously more aware that it’s bacteria they’re dealing with) and it can be regulated far easier. The Science Fair suggests using normal agar, dirty fingers and then cinnamon and curry oil to watch the bacterial growth. I wonder if it would work with direct contamination of a bacteria (like the E. coli we always have) and then either disks of different oils or a dilution range of oils or a plate for each oil. One of our Microbiology stock experiments is using different hand soaps on disks to see its effects on E. coli, how about adding in an oil? Or more food preservatives? This could be handy in a food storage unit.

Definitely one to try. Either version!

Merry Christmas from the Science Learning Centres | National Science Learning Network Blog

Merry Christmas from the Science Learning Centres | National Science Learning Network Blog.

This is a link to two videos from the National Science Learning Centre – both of them linked to Christmas! The first is aimed more at primary aged children with snow and winter in mind. I’m sure you can do it even if you’re older in age (and young in mind perhaps). The video makes it look very simple, perhaps even to get an older set of students to plan it all and experiment themselves with differing amounts/types of salt and watching how fast the ice/snow melts.

I don’t think it would be too difficult to adapt to do at home with younger children either. Especially as nothing involved is hazardous or toxic (if you stick to salt). I’ve always wanted to try ice and salt based activities with normal table salt and reduced sodium salt. Add in rock salt and you have a nice little experiment.

The second video is for secondary aged students and based around experiments you can do at the Christmas table.

Merry Christmas!