HOME MADE INDICATORS

The classic way to make your own indicator whether it is as a liquid or paper is to use red cabbage which is readily available at this time of year in the UK.

I think the easiest way to do it is to chop up the cabbage - depending on how much indicator you are making you will probably only need a quarter -  and boil in water until it is soft. 

Discard the cabbage and keep the now purple liquid. Once cool you have your indicator - one small tip red cabbage juice smells  and it gets worse the longer you keep it!

BTW I know that many high schools and chemists extract the indicator using solvents but I really think it works just as well using water and boiling up plus primary schools often won't have access to chemicals but use whatever method you want to.

If you are making indicator paper I have found the best  to use is cheap watercolour paper in a pad. You could use coffee filter paper or even school filters but art paper is by far the cheapest and  available in large sheets.
Use a large tray and immerse the paper then let it soak up the colour. Let it dry and cut into strips - there you have it.

You can use larger pieces for pH painting where you dip either cheap paintbrushes or cotton buds into solutions of different pH such as clear vinegar, bicarbonate of soda and then when you paint you will get different colours depending on the pH of the liquid.

You will get reds and pinks in acids, purple in neutral and greens and blues in alkali.

If you don't want the smell of cabbage or you want to do this is summer then you can use pretty much any plant that has a purple colour - squish them up and use the juice. Blackberries work well.

some children testing household solutions with indicator paper we have made

At this time of year poinsettia plants are all over the place and the red bracts chopped up and gently cooked ( or extracted with solvent) give a reddish juice which again is an indicator.

This brilliant poster is part of CompoundChemical's advent calendar which if you are not following it you need to do!

At the time of writing this is the live link

http://www.compoundchem.com/2016advent/

The posters are so good that I am sure they will be archived

Many red and purple plants contain anthocyanins—you may have read about a colourful diet being healthy due to this group. You can also see it in roses and most easily hydrangea which can be turned red or blue by changing the pH of the soil they are growing in.

There are other natural indicators—Turmeric is one, going bright red in alkaline solutions—you don’t get a range of colours but it is quite a startling colour change and great for pH painting.

the change from yellow to bright red 

Fascinating Fact: did you know that litmus paper was made from lichen??

Classroom Display Competition

Do you have great wall displays in your school?
Are you a creative talent when it comes to displays for science?

STEM Learning have launched a competition to find great ideas and resources using classroom displays. You could win £200 of your choice of vouchers.

All you need to do is photograph your display and have files for supporting work that go with it and enter!
Here is the link to the main page for entries.
https://www.stem.org.uk/news/display-your-talents

There are two categories - primary and secondary.

It couldn't be easier!

Closing date for uploading your entry is 7th December and the winners will be notified on 14th so justs in time for a Christmas treat!

If you are stuck for ideas just browse online - so many teachers here and abroad share their work and many are rightly proud of their displays.

I just searched for science classroom displays on Pinterest ( that ever expanding resource) and found so many stunning images.

Do you remember Belair the books all about amazing displays? They are still around - published by Collins and they have some on science.
http://www.collins.co.uk/

I also found lots of older Belair books on ebay really cheaply...always worth a look for inspiration.

Here are just a few ideas to whet your appetite:

with thanks to all the wonderful teachers, technicians and classroom assistants for sharing their work on Pinterest

Bonfire night chemistry

This weekend in the UK we look forward to one of our traditional celebrations - Bonfire Night.

The hour has changed so it is dark early enough to have a bonfire and set off fireworks or to go to an organised event.

 Compound Interest have some super posters and articles explaining the science behind not only the colours but also the sounds of fireworks.

this is a great poster - all you ever wanted to know

so now you know how a firework whistles!

I really recommend you visit the website because there are super articles to go with the posters.

http://www.compoundchem.com/

Halloween Science

It is close to that time of year again!
Here are some ideas for fun experiments. Just check out Pinterest to see what those amazing American home school mums get up to.

Fill some thin latex gloves with coloured water and spooky bits such as plastic spiders, googly eyes etc then freeze.

Once frozen you can either use warm water and drizzle over or sprinkle salt and watch the hands slowly melt revealing the spooky bits. Lots of fun for small folk!

You've probably tried  using vinegar and bicarbonate of soda to blow up a balloon. But why not try this alternative for Halloween - a white balloon with ghost eyes and mouth. Another idea is to do the freaky hand using a thin latex glove which you can draw fingernails on or make it have hairy knuckles.

Of course we have to go one better... it took quite a bit of tweaking to get the right amount of vinegar and bicarb to blow this veterinary examination glove up.

I came across this gloriously messy activity on Pinterest - a bowl full of the most gruesome gunge and other creepy stuff covered in bubbles. The brave victim has to feel through the bubbles revealing the "horrors" beneath. (Not sure why but the pasta freaks me out the most!)

This is a brilliant idea from Left Brain Craft Brain

Using a brain mould - I went on AmazonUK and found lots of different ones in all sizes including life size. You can fill the mould with a variety of gungy materials. They have used left over cornflour gloop which was quite thick but you could make this edible using jelly with spooky sweets in it or green coloured blancmange. 

http://leftbraincraftbrain.com/

I love this slime with added spooky bits

Here is a slightly different take on slime - I love the eyes. This is really for those who don't want the mess everywhere or for really little ones who wouldn't be able to resist trying a bite! Sensory bags are great fun at any time of the year but this is super for Halloween.

There are so many different slime recipes around. You will see PVA school glue used which gives an opaque result but American's often use clear Elmer's school glue for this transparent effect. I have discovered that you can buy it now on AmazonUK and you can still get Borax - there is nothing else that will produce the wonderful slime effect as well. You will probably have to go online for it since the EU directive ban on it as a food substance and cleaning additive.

Finally I thought you might like to see this........

A few years ago we did a Spooky Science show at Catalyst Science Discovery Centre and created this pumpkin puke demo.

This can be done using the classic Elephant's toothpaste which is hydrogen peroxide, washing up liquid and either potassium or sodium iodide. The result is spectacular but messy because of the iodine yellow everywhere plus we wanted to be able to repeat this demo four times a day for a week so clearing up the mess everytime wasn't an option.

So we used what is often called the "safe" method using hydrogen peroxide, liquid soap and a warm solution of dried yeast. After a bit of tweaking the result was pretty great!
If you follow the link you can find a short YouTube clip

https://www.youtube.com/watch?v=eq1ESBh-kDU

Have a great Halloween and enjoy the science!

ALL CHANGE

Welcome readers and blog followers

Science2U publishes an electronic newsletter which until now has been monthly.
As you can imagine this takes quite a bit of effort and this blog has suffered as a result.

So we have decided to make the newsletter half termly and any extras/news etc will be published on this blog.

So for our first bit of news.

British Science Week 2017 10th - 19th March

There are grants available to help you fund a science event.
Up to £300 for a school event
Up to £700 for an event which involves your school and wider community
Between £500 and £1000 for those falling in the under represented in science community group.


We have worked with schools who have qualified for funding and I thought you might be interested to hear of a couple.

One school went for a Kickstart more grant which involved their local community.
They booked us for a morning of shows with the pupils and then the afternoon had two hands on session with families. Staff helped us to run a fun workshop of experiments for all the family.

Another school used their money to book us for an extra long day of shows - school children in the morning, family in the afternoon and an early evening open event for their  village.

One idea we had was to work with some pupils to help them put on a science show for the wider community - great for your budding science presenters

It is definitely worth looking into seeing whether you could organise an event that would qualify.

Have fun!!

SUMMER SCIENCE SNIPPETS - OUCH THAT HURTS!

STINGS!!!

As I am writing this blog I am noticing that it is now wasp season!
August seems to be their peak - certainly in my garden.

I live near a marsh and the mosquitoes are like vampires leaving a huge welt and very itchy!

 A day at my favourite beach reveals more and more jellyish on the sand and don't even get me started on the ants!!

Pretty much the only ravenous insect I encourage are the bees and fortunately my garden is full of them. I have finally managed to get enough plants to bring them in.

A day at the beach especially with a picnic can be a science lesson in the local biting and stinging wildlife.
So what is in a sting or bite and are those old wives tales for treatment really true??


Blue bag for a bee and vinegar for a wasp?

Do you really need to pee on a jellyfish sting??

A little bit of science can help you out.

There are so many websites giving advice for "natural" cures for stings and repellents. It is worth a look but in the panic of a painful sting will you remember what to do??

Bee Sting

Common knowledge says that bee venom is acidic so using a bicarbonate of soda paste will neutralise it and help with the pain. The calming effect of bicarbonate is true - it really does reduce itching and is useful for mosquito bites.


It is true that many bees have a sting that is barbed and will lodge in the skin of a mammal or bird pulling the sting from the abdomen of the bee and killing it. So most bees rarely sting unless on purpose. Their sting is used for inter bee battles when the hive is threatened.
Bee stings are amazingly complex with peptides to break down cells which releases histamines and this is where people with allergic reactions have trouble .
For most of us doctors usually recommend ice to reduce inflammation and give a mild anaesthetic effect with an antihistamine cream .

Wasp Sting

The alkaline nature of a wasp sting has led to old wives tales of vinegar or lemon juice to neutralise the sting. As with a bee sting it is unlikely that this will really happen and will probably hurt because one of the things in wasp venom is acetylcholine which stimulates pain receptors - there is even more of this in a hornet sting.

Ant Bite

Wasp and bee venom varies a little from species to species but ants vary markedly. So it can help to know what has bitten you.
Some ants don't bite but spray formic acid and some use their venom to neutralise attacking ants of a different species!

One final thing in all these insects venom is an alarm pheromone so if you have been stung and kill the insect others will know.........



Jelly Fish

There are more and more jellyfish on our beaches and of course abroad. So there you are splashing around and suddenly you feel a stinging hot pain....yes you've brushed up against a jellyfish or tentacle portion in the water.
The harpoon like cells penetrate your skin easily and inject venom which is designed to paralyse and kill fish and depending on the species will raise a painful welt, blister or make you very ill indeed and could kill you.
However before we all race off the beaches - the sting of most jellyfish found around British water is painful but not lethal.
So having seen that episode of Friends you run off to find someone to pee on you? Well no - because pouring fresh water - including urine - onto a jellyfish sting releases even more venom so experts suggest remove all trace of the tentacle and then  rinse in plenty of salty water and very recent research suggest that hot salty water is best.

Mosquitoes

The female causes the problem and she doesn't actually bite you - she uses her proboscis, which is razor sharp, to pierce your skin and drinks some blood which she can use in the production of eggs. As she finishes and flies away she leaves some of her saliva in the wound which can contain diseases - malaria and zika virus being just two.
Your body reacts to the saliva producing histamine - so tissue swelling, itching and redness. People reacts differently some quite violently and an infected bite can need antibiotics but usually antihistamine will work.
If you are into natural remedies lavender oil works too - and scientists have researched that one.

The best remedy is not to get bitten at all so how do you repel them?
Insect repellants usually produce an odour that insects don't like and so they stay away.
There are plenty of insect repellents that you can buy over the counter which work in similar ways DEET being one well known brand. It does have a greasy feel and unpleasant odour so many people turn to "natural" products and at the moment the trend is for lemon eucalyptus oil. Citronella candles and spray can work too


So sadly the old wives tales/home remedy methods usually over simplify the situation and many don't work at all.
Probably your best bet is ice to reduce the pain and antihistamine for the inflammation  for ant, bee and wasp and warm salty water for a jellyfish.

Have fun!!

PS: For those of you wanting a little more serious science facts here are two amazing  Chemical Compound posters from Compound Interest   http://www.compoundchem.com/

SUMMER SCIENCE SNIPPETS - COOL SHADES

THE SCIENCE BEHIND YOUR FAVOURITE SUNGLASSES

Whether you opt for heart shaped,the John Lennon look or wrap arounds you do need to protect your eyes from the sun.

The eyes are especially susceptible to the sun because of the transparency of the outer tissues. Long-term exposure can speed up ageing of the macula, the most sensitive part of the retina and can also lead to cataracts.

Look for sunglasses that meet the European safety standards. This means they will be of good optical quality with break-resistant lenses, providing high levels of protection against ultraviolet light, while not distorting colours. It's worth buying a pair with a dark tint and with plastic rather than glass lenses, for safety reasons. One of the key functions of sunglasses is to reduce the amount of sunlight entering the eye. Look for a pair offering a light reduction of up to 80%, that is they will allow in only 20% of the sunlight. The size of the lens - the area shielded - affects light admitted.

 Expensive sometimes means better, but not necessarily. What really counts is the degree to which the lenses filter out harmful UV rays. Look for the CE mark, which proves they conform to the European Community Standard. They should also satisfy British Standard BSEN1836, meaning they will provide high levels of protection against damaging ultraviolet light.

 Don't confuse the shade of the lenses with their ability to filter UV rays. Dark sunglasses may still allow UV rays to enter the eye. 

 Polarising lenses will reduce reflective glare from water and land surfaces, making them particularly good at improving vision in bright or hazy driving conditions.

What about if you wear glasses either for reading or everyday?
Photochromic lenses were invented in the USA  back in the 1960s but were very expensive when they first came to Britain and could be very slow to react.
The original lenses that darkened when exposed to UV rays were made from glass and although the technology has improved especially the speeding up of reaction time the science is still basically the same.
Glass photochrome lenses contain silver chloride crystals that when exposed to UV-A light ( 320 - 400nm) actually make dark elemental silver  & when in the shade the silver reverts to an ionic state and the lenses go clear.

Plastic lenses are different because they use photochromic dyes which rearrange in UV to give darker colours. The dyes need to be in specialist plastics and each company has its own proprietary polymer. Some even sandwich the dye between the plastic. It is an area of lucrative research with a huge market.
The next generation of transitional lenses hope to deal with the fact that drivers can't really use them because many car windscreens actually have a UV blocking coating effectively stopping the sunglasses working.

And in the future?.........
The very latest technology announced recently uses an electrochromic polymer changing colour with electricity

Chemical engineer student Chunye Xu and colleagues from Seattle have been working on "smart" sunglasses that can lighten or darken on command.

Using power from a watch battery the polymer can change shade in one second with milliwatts of power when the button on the side arm is pressed.

Electrochromic polymers are not new but this application uses such a small amount of power and is very quick to respond.

As a prototype they are rather heavy but have real possibilities. The team are also working on glasses to correct sight defects.