Forensic Science: Chromatography

Hopefully will one day put up my forensic science experiments which the students enjoyed but I want to link them all into a crime story so you can work through it figuring out clues. Just haven't quite planned it all out yet - will be a summer holidays project I think.

But I would like to share some photos of students doing chromatography in class. Really simple procedure.

Need per pen to be tested:
1 cup (clear plastic is best)
1 paddle pop stick
1 strip of chromatography paper or coffee filter paper - I could only find brown on short notice but I do know you can order chromatography paper in bulk and tbh brown wasn't too bad for what we were looking at.
Black marker
Water

Procedure:
Place a dot from the black marker about 1 cm from the bottom of the strip.
Put some water in the bottom of the cup - doesn't need to be too much.
Wrap the strip around the paddle pop stick so that when placed on top of the cup it is just touching the water. The dot should not be submersed in the water.

Watch the magic.

Oh and don't try permanent marker ... made this very stupid mistake and was wondering why it wasn't working - permanent markers do not separate in water. You just end up with a wet piece of paper with a black dot on the end.

Will put up some detailed instructions and worksheet when I get time soon with the science explained.

Random Name Selection

So hands up everyone if you have a jar or container of paddle pop sticks with student names on them (or something along those lines).

I used to have this for questioning in class (now I am trying to do student led discussioins but that is a whole other post). This stops the same students carrying the class through question time and also the same students sitting back and either being lazy or too shy to answer.

I absolutely love random name generators and the students do too. It means that they are always listening because they don't know whether they will be asked a question and it also means that they start to listen to their peers as I penalise if they say the same thing with no added information due to them not listening. It also stops the jiggling with the hand in the air which can be distracting to those people that are still trying to think.

Now to make it more interesting, I have discovered the world of technology and therefore the world of interactive student name generators. This has made it more fun for students too, as they love watching to see if their name is drawn. There are positives and negatives to this approach though.

Positives - means students believe that the process is random, rather than you selecting from a cup (seriously they never trust you); the students are engaged as it is technology and interactive and there are lots of different types so you can change it up; setting up for groups is easier as some even allow different groups which means you don't have to sort your paddle pop sticks or have different sets.

Negatives - involves technology which can have problems (I still keep my paddle pop sticks as a backup just in case something is not working on the technology front); means you can't necessarily scaffold students to certain questions as easily as you could picking out from the jar (sometimes this doesn't matter however sometimes I want certain kids to extend themselves).

MY PICK

Dart Board Selector

My students absolutely loved this. You can even have names removed as you hit them which makes it great when making sure everyone has a turn.

You do have to create an account however a free account allows you to use the different tools. This means however that you can save different lists of names or words, which makes it a quick and easy tool after setup.

OTHER OPTIONS

Random Name Selector

Allows you to randomly pick a name. Once you have entered the names, click go and the name is selected and said aloud. You are given several choices on time and whether you want the name removed from the list. 

The Hat

This is one to download. You can add your list of students and either pull one name or pair of names. It is random and it won't call the same student twice. 

Magic 8 Ball

Another download one however it has an interesting option of turning on weighting which allows you to note which students get the answers right and wrong, the students then are more likely to be drawn up if they have got an answer wrong than right. 

Fruit Machine

Not quite sold on this one due to the gambling element. Still it is another generator you can use. You can remove names as you go.

Oh and don't forget these aren't limited to your class names. You can list words, groups, numbers, activities etc.

Do you still use paddle pop sticks? Are there any other random name pickers that you have found that you would like to share?

Class choice of reading book

So ... choice can allow students to choose what they want to do which generally leads to them being more engaged and interested in what we are doing in class. Of course it can backfire too so you have to be reasonably prepared to either change the votes slightly or only offer what you are happy to teach.

I decided this term that I wanted to do a compare and contrast with a novel and a movie.

I asked the students to suggest books that had movie adaptations which we would vote from. I added in some suggestions as well.

The students came up with some fantastic choices including:
- The lion, the witch and the wardrobe
- Owls of Ga'Hoole
- Bridge to Terabithia
- Coraline

- His Dark Materials
- Eragon
- Harry Potter
- Charlie and the Chocolate Factory
- Charlottes Web
- The Polar Express
- James and the Giant Peach
- Ratatouille
- The Witches
- Gulliver's Travels

The students then voted. It came down to a close call between Coraline and Percy Jackson - with Percy Jackson winning by 2. Of course we did full preferential voting.

So currently I am creating an amazing unit as I teach it for this book and movie.