Friday, 28 August 2015

Elements and Atoms

After exploring the Periodic Table we decided to delve in a little deeper and explore what exactly makes up an atom and how does that relate to the periodic table?

First off we discussed how atoms were discovered.  After reading this very informative post from Our Worldwide classroom we talked about how around 400 BCE the Greek philosopher Democritius experimented with trying to cut gold in half as many times as he could.    He called this unit the atom which in Greek means "uncuttable".  
In 1910 this experiment was replicated with gold foil by Sir Rutherford.  L tried it out with a piece of paper and scissors.  I think she managed 17 cuts.  According to Google you would need to cut it in half 31 times to get it down to an atom.  L thought that was pretty impressive.

We then watched this excellent Youtube video on atomic structure which helped us to learn about protons, neutrons and electrons and how the number of protons in the nucleus is how the atomic number is determined.  We also learned how there are different atomic shells which hold a certain number of electrons.  

After watching the video L was able to figure out how to make models of different elements.  
This is where the fun really began.  We headed down to the beach and collected a bunch of black similar sized stones.  We then separated them into three piles for protons, neutrons and electrons and painted them each a different colour.  (Even little brother had his own pile to paint).  Once dry we put the electrical charges on them.
As you can see in the pictures L used her hula hoops for the outer shells and using her periodic table was able to create the atoms of different elements.

She also made a 3d model of an element as a mobile.  It turned out really cool but we had a bit of a time getting there.
L decided she wanted to make the element titanium.  It was all well.  She'd figured out how many protons by the atomic number and then the number of neutrons by subtracting that number from the atomic weight.
The number of electrons was also easy and we thought which shells they went in was straight forward according to the rules of the video we watched.  Well after much Googling by the parents we finally figured out that several transition elements actually don't fill up the third shell before adding another shell.  It gets very confusing so I won't get into it here.  My brain still hurts!

Anyhow the final product is stunning.  It was really simple to make.  L glued pompoms together for the protons and neutrons in the nucleus.  We cut out different sized pieces of cardboard for the outer shells and L painted them sliver then glued on the electrons to their appropriate shells.  We hung them all with invisible thread.  What a great way to visualize an atom!

Tuesday, 25 August 2015

The Periodic Table

It seems I can't hold L off any longer.  I've been promising to start chemistry as soon as we finished DNA and genetics, however L was just too curious about this whole periodic table thing to wait any longer.

The great thing about learning chemistry these days is that there are so many incredible resources out there.  This post will be mainly about sharing all of these amazing resources that we are using.

The first thing that I think is a must is this fantastic free periodic table printable.
You can download it here.

You can also print off cards to go with each element.  They are perfect for different card games, organizing elements by different groups etc.  Even though the cards have the atomic symbol on them I printed them out again for L to match.  One note is that they take an incredible amount of ink.  I only printed out about half of them and we are now out of ink so the rest of the cards are "pending".

I think my all time favourite resource is this super catchy periodic table song.

L has taken it upon herself to learn it all!  She's about a 3rd of the way through at the moment.  If you google words for the song you can print them out which makes learning it a lot easier.  Of course this is if you can handle hearing it 24/7!

Another resource that is not absolutely necessary but super cool is an app called The Elements.  It is an interactive periodic table.  You can click on each element and there is a write up plus different real life examples of the element.  I can't do the greatest job explaining it but check out this youtube video

I went for the full bundle and got Elements, Molecules and In Action.  I also got the free app goReact in which you can choose different elements and make your own chemical reactions.  Very cool.  L enjoys exploring the different elements and seeing how they react with each other.

We also got the book The Periodic Table: Elements with Style by Simon Basher out from the library.  L is not a fan of the illustrations at all but has flipped through it a bit.  Others who are in to this kind of comic book type style might really dig it.

Learning chemistry is so different from the days when I was in high school and things were as boring as could be!

Monday, 24 August 2015

DNA-replication, translation and transcription

This whole DNA business can be a pretty complicated subject, however there are so many amazing resources these days that it makes learning about it fairly accessible.

For DNA replication we started off with this great video which really simplifies the whole process and makes it easy to understand.   I added in the enzymes as well as some other cards necessary to split apart our DNA and replicate it.

I've taken some pictures of how we applied it to our DNA game.  I'm sure some of you with sharp eyes can spot my grave error on two of the bases.  I just set this up quickly to take demo pictures and by the time I noticed the error I didn't want to retake all the pics.  Just think of it as a mutation!

 Anyhow you start of with the helices splitting things apart.  I'm not going to explain the whole process here as you can just watch the above video to see how it works.  

By the end we have found the extra bases to complete the new strand and have replicated our DNA.  L found this a great way to really see how the whole process works.

We also did a worksheet on transcription and translation that can be found here.
L found this easy as we'd already played the transcription game which helped us to learn how the DNA is turned into RNA and then the RNA bases are read in codons(or groups of 3) to make up an animo acid.  These amino acids combine together to make a protein.  It all sounds very complicated but the game makes it so much simpler.