It is an honour as well as an exciting moment for me to type these words as this is the international year of chemistry. I have been formally in chemistry since the day I left school back in 1986, however, that spark which ignited this passion for chemistry flashed many years earlier, in about 1974.
Let me quickly tell a little story.
At the age of six my family gathered around the fire one November night under the Karoo sky. My dad ignited some fireworks, while we qualified to hold sparklers.
For myself and my twin brother this was pure delight.
Soon the last firework was spent and my hopes dimmed from the exciting flashes and bangs.
From that moment on, the desire to see of these spectacular flashes once more burned with ever increasing brilliance and I turned excitedly to Encyclopaedia Britannica, my twin brother alongside. Farmer dad and ballet teacher mom could not help us much so we had to do it on our own. We did, the slow way. Many years, and hundreds of experiments later I created my own fireworks, rockets and tremendous bangs which far exceeded the normal home fireworks - this was in my seconds year of studies in Analytical Chemistry at the then PE Technikon in 1987.
Seemingly small events made big changes in my life and steered my interest. This happens to You too. I was fortunate to be taught by Padre Dixon at Union High school in Graaff Reinet - he was tremendously enthusiastic and was always doing chemistry and physics demos for us.
Unfortunately many schools are crippled by budgets that do not permit young potential scientists the opportunity to learn by seeing the thing they are learning about. I find this all the time when lecturing students and it saddens me.
What can be done about it? Occasional visits by university staff to schools are possible but there are many schools and time does not permit.
Being the International Year of Chemistry I thought it fit to begin to use the tools we have in this modern world to bring chemistry to you in the form of this blog site. It is called Chemistry and You for a good reason. Chemistry affects you and everyone else far more that we may realize.
My fellow staff and I am going to bring you a lot of chemistry in the form of short posts, pictures, video clips on Youtube (yes, you can see what we do in the labs). Also we will use social media such as Twitter and Facebook.
I am Dr Gletwyn Rubidge of the Nelson Mandela Metropolitan University, I look forward to making regular contact with you.
Now let us waste no time and get on with it...
I spoke about fireworks kindling my interest in chemistry.
You have surely all seen fireworks.
Ever wondered what makes them work - what makes the colours, the bangs, the smoke?
Colour in Fireworks:
I set off three 1000 foot flares at a new years party - as you can expect my 7 year old son loved it. One question he asked me was how does it get to be so bright red.
I explained that it is a type of gunpowder inside the flare that burns very hot (about 3000degC) and it has an element called strontium in it. The heat causes the atoms to become free - kind of floating about. Normally the atoms are bound to some other atom but at this temperature they are mostly separated from one another. In this free state the outer electron in the atoms can get excited and moves to a higher energy state. Kind of like you climbing up to a branch in a tree. When it calms down or relaxes it can release energy as light. Strontium can release red light as it relaxes back to the lower energy state.
Yes, you guessed it, that red light you see is from strontium added to the gunpowder in the flare.
Here I put some strontium into an air acetylene flame at about 2400 deg C - normally light blue like a gas stoves blue flame - the strontium makes the flame a strong red colour.
How do they make green?
Barium gives a light apple green colour.
Sodium gives an orange-yellow - the same colour you see in some of the street lamps such as in Target Kloof, PE.
Have you ever seen some water boil over from a pot onto a gas stove - the blue flame goes yellow. It is mostly sodium light you see in that flame.
Potassium yields a lilac colour.
Calcium forms a brick red colour
Copper forms a blue-green
In my next post I will cover how we can use these colours for analysing these elements and many more.
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