STEM

Are you attractive!

In STEM Club this week the focus was on magnetism and magnetic fields.  The children performed a series of experiments which included using iron filings and various magnets to visualise their magnetic fields, creating a 3D magnetic field viewer (using baby oil!) and experimenting with magnetic slime.

Technical Stuff

Magnetism is a force that attracts or repels objects that have a magnetic material, like iron, inside them.  The magnetic force is made up of magnetic fields, which are invisible to the human eye.

Magnets can attract materials such as:

• Iron
• Steel
• Nickel
• Cobalt

Using Iron Filings

Using iron filings and different types of magnets, including bar, horseshoe, circular and square magnets, the children could see the magnetic field patterns produced by the alignment of the iron filings when the magnet was placed underneath the sheet of paper – a rather messy start as the iron filings got everywhere!

Magnetic 3D field viewer

The children added ½ tsp of iron filings to a small glass bottle filled with baby oil.  With all the air removed and the bottle sealed, the children looked at the 3D magnetic fields created inside the bottle when one or two magnets were brought close to the bottle.  This was a great experiment to see how the different magnetic poles attract or repel each other.

Mr Herbert’s Big Magnet

Using Mr Herbert’s homemade magnetic slime, the children brought a magnet close to it and watched the effects on the slime; from creating slime tentacles to seeing a magnet completed consumed by the slime … another fun but messy experiment!

What a reaction!

In STEM Club this week the focus was on chemistry which included a series of fun experiments looking at chemical reactions, for example,  when a base element is mixed with an acidic element. 

The children performed a series of experiments, using sodium bicarbonate, citric acid and water. Each experiment was designed to show what was produced and how much was produced during this reaction.

Technical Stuff

When sodium bicarbonate, citric acid and water are mixed together, they yield sodium citrate, water and carbon dioxide gas. The resultant yield from this chemical reaction is larger than the original components i.e. it produces a lot of CO2 gas.

The First Reaction 

Children mixed Sodium Bicarbonate, Citric Acid and water into a dish. Children could see the reaction fizzying and popping as it produced the CO2 gas. 

Orange Fizz 

This experiment involved sprinkling Sodium Bicarbonate (and icing sugar) on a slice of orange.  Children tasted the orange to feel the effect of the reaction, a bit like eating sherbet!

Inflating a Balloon 

Children put a small amount of sodium bicarbonate and citric acid into a balloon. They then added water to a test tube and wrapped the balloon over the top of the test tube. They spilled the mixture into the water so the reaction could begin. This experiment was designed to show children that even though we started with small amounts of ingredients, they produced more CO2 gas as they reacted and inflated the balloon. 

Rocket Canister Launcher 

We now had evidence that a lot of CO2 gas can be produced. We then looked at how this could be used to launch a canister (rocket) into the air. Children mixed the sodium bicarbonate and citric acid into the canister followed by a small amount of water, quickly adding the lid and dropping this into the launcher upside down. 

After several seconds, the CO2 gas forced the lid to pop off and the rocket was launched several metres in the air.

Cosmic Launcher

Finally, we went outside into the playground and launched our newly purchased Cosmic Launcher. This used all the same principles from the previous experiments but was designed to achieve launch heights of 20m. After many seconds we thought the rocket was not going to launch but then “bang!” it propelled about 10-15m into the air miraculously!