demonstration

Diffusion and Osmosis using raw egg

Remove shell of raw quail egg by soaking it in Hydrochloric acid or vinegar for a day. Rinse it and place it in various set-up to demonstrate diffusion and osmosis.

From left to right:

Untreated, in distilled water, in red-coloured water, in honey.

Advertisements

Heat demonstration

Kids were amazed with convection demonstration today.

They went “wow” when they saw the red dye reversed its direction. Love their expression! If only I could snap a photo of their wide-eyed reaction. hahaa.. This is why I enjoy doing demonstration 🙂

The kids also had fun with a “magic liquid”.

They kept asking me where to buy it and I was like… I don’t even know what this “toy” is called to google to buy it.

Also did metal ball and metal ring, but not much excitement as these two demo.

Red cabbage indicator

My favourite demo for the chapter on acid and alkali is…

red cabbage indicator

Add a pieces few leaves of red cabbage into a beaker of hot water. The leaves will decolourise and the solution will eventually turn purple. We will use this solution as the indicator. Add 2 drops into different samples and observe for colour change.

red-cabbage-indicator

Colourful results from red cabbage indicator

Here’s my colourful result using these samples (from yellow, clockwise)
Lye water, bicarbonate of soda, sprite, detergent, lemon

Best used with samples that are colourless.

You can encourage students’ participation by allowing them to bring their own samples. Students generally are more excited to work on stuff that they contributed.

You can also extend this activity by giving them time to make their own indicator paper which they can bring home. Simply cut strips of filter paper, soak it in red cabbage juice and let it air dry. Students can then use them by dipping it into samples.

Sources of light

To introduce to students that light is a form of energy, I usually highlight some examples of energy changes to light energy.

Here are some stuff I use for to demonstrate the energy conversion…

light-energy

Different sources of light energy

Dynamo torch (bought on Carousell):
Kinetic energy to to electrical energy to light energy light energy

Solar chasing light (bought in Kmart, Australia):
Solar energy to electrical energy to light energy

Light bulb:
Chemical energy to electrical energy to light energy

Torchlight:
Chemical energy to electrical energy to light energy