TERM THREE BEGINS...
WITH A TASTE OF SCIENCE...
WE'VE BEEN SO FORTUNATE TO HAVE MAD SCIENCE COME IN ENGAGE US IN THREE SCIENCE WORKSHOPS
WORKSHOP ONE: JUNIOR REACTORS
KEY CONCEPTS WE LEARNT…
- A physical change happens when only the SHAPE of a compound changes.
- A chemical change happens when the molecules of a compound change.
There are four cluesthat let us know when a chemical change takes place in a reaction:
1. gas bubbles form
2. the colour changes
3. temperature changes
4. a new compound/substance is formed
some reactions have more than one clue
EVERYTHING is made of ATOMS, which are so tiny that they cannot been seen with the naked eye, or even under microscope
ATOMS group together to form MOLECULES which form a compound/substance.
- Think about the clothing you wear, it's made up of ATOMS
- Think about the food you eat, it's made up of ATOMS
- Think about the chair you sit in, it's made of ATOMS
- think about the books you read, it's made up of ATOMS
WORKSHOP TWO: CHEM IN A FLASH
KEY CONCEPTS WE LEARNT…
- An action that causes a reaction is called a stimulus
- Chemical reactions can be fast or slow depending on how molecules react to a stimulus
- The rate of a reaction can also depend on the amount of stimulus needed to cause the reaction
- Acid mixed with salt creates a strong cleaner that can remove copper oxide off a penny
ONE EXPERIMENT WE DID WAS TO MAKE COPPER PENNIES TARNISH (CAUSE OXIDATION) AND THEN TO REMOVE THE TARNISH
OXIDATION
COPPER PENNIES
We used HYDROGEN PEROXIDE to accelerate the oxidation process on copper pennies. They turned slightly green which proves that oxidation took place. It happened more quickly because hydrogen peroxide contains more oxygen than water.
To remove the copper oxide (rust/green tarnish) from the pennies first we tried to wash them in a solution of dish washing soap and water. This never worked, they remained tarnished.
Next we tried to clean them in diluted acetic acid (vinegar). They still remained tarnished.
Finally, we added salt to the acetic acid (vinegar), stirred our pennies around and the copper oxide came off, they were bright and clean again.
WORKSHOP THREE: pH FACTOR
Key concepts we learnt…
A pH scale measures the chemical hydrogen ion to tell whether a liquid is an ACID or BASE
ACIDS have small pH numbers (0-6)
BASES have big pH numbers (8-14)
NEUTRAL chemicals have a pH number of seven and are safe for our bodies (7)
Liquids that measure VERY HIGH or LOW numbers on the pH scale are dangerous
We should stay away from bottles labelled with danger signs such as:
CORROSIVE EXPLOSIVE FLAMMABLE POISONOUS
IMPORTANT INFORMATION about the pH scale:
Just like there are very high and low temperatures on a thermometer, there are very strong acids and bases at opposite ends of the pH scale.
These extreme ends of the scale are very DANGEROUS
Just like we wear gloves to touch something very hot or cold, we must wear gloves to touch chemicals that are very ACIDIC or BASIC
READ WHAT CATHERINE AND MARIA THOUGHT ABOUT JUST ONE OF THE WORKSHOPS...
A Staggering Reaction
On Tuesday morning, in class we were working on our maths, when suddenly the bell rang and Mrs Massari, our teacher announced that after morning tea we would be attending a stunning science workshop. We were so overwhelmed and excited that we couldn't stop chattering, while waiting for Cosmic Chemical Claudia to appear.
Entering the workshop in the hall we were bowled over by the interesting looking experiments that Cosmic Chemical Claudia was preparing for us… This is when things became more intriguing, each group was given a tray and on it were 3 different substances that we needed to use to create some staggering reactions. The critical chemicals we used were sodium bicarb, citric acid and bromothymol orange indicator. These substances created amazing chemical and shocking physical reactions. Did you know that when a chemical reaction occurs there is usually a change of colour, substance, and temperature or sometimes there will be bubbles, fizzing and foaming?
We certainly learnt some stunning facts. One of the most interesting facts was that everything… we mean everything, is made of millions and trillions of minute microscopic atoms. Did you know that a single atom cannot be seen by the human eye or even with a microscope, because these microns only measure 0.0001 (a millionth) of a millimetre?