This week in 5th Class, we have been investigating materials and their properties.

Experiment 1: Does it Conduct or Insulate?

Equipment: 2 Crocodile clips, 1 bulb, 1 bulb holder, 2 batteries, a battery holder, a match stick, a metal spoon, a pair scissors, a piece of tinfoil, a plastic spoon, a piece of paper, a shoe lace, a rubber.

Method:

Step 1: Set up a circuit using the crocodile clips, a bulb, a bulb holder, batteries and a battery holder. Check that the circuit is working (the bulb will light up).

Step 2: Make a prediction as to whether the objects are conductors (let the electrons through to the light bulb) or insulators (stop the electrons from passing through to the light bulb).

Step 3: Test whether the various objects are insulators or conductors by connecting them to the circuit.

Results from Group 1:

Matchstick: Insulator

Metal spoon: Conductor

Scissors: Conductor

Tinfoil: Conductor

Plastic spoon: Insulator

Paper: Insulator

Shoe lace: Insulator

Rubber: Insulator

What we learned:

An insulator is an object made from a material that electricity cannot flow through. A conductor is an object made from a material that electricity can flow through. If the bulb does not light up when you place an object across the gap in the circuit, then the object is an insulator. If the bulb does light up then the object you are testing is a conductor.

Experiment 2: How Quickly Does it Fall?

Equipment: Maple syrup, honey, oil, vinegar, 4 clear plastic cups of the same size, 4 balls of play doh (they must be the same size to make it a fair experiment).

Method:

Step 1: Fill up each cup with a different liquid. Ensure that they are all even to make it a fair experiment.

Step 2: Drop a ball of play doh into the first liquid. Time how long it takes to get to the bottom of the cup. Record your result. Do this with all of the liquids.

Results from Group 2:

The vinegar let the ball fall the quickest (1 second) with the oil coming in at a close second (1.5 seconds). Unfortunately, the play doh was too light and so it floated in the maple syrup and honey.

What we learned:

Liquid resistance slows moving objects. Also, we should have used a heavier substance to drop into the liquids such as modelling clay. This would have ensured the object went to the bottom.

Experiment 3: How Quickly Does a Gas Move?

Equipment: Perfume, vanilla essence, vinegar, stopwatch

A (The Smeller)

B (The Opener)

Method:

Step 1: Predict which smell you think will travel the quickest.

Step 2: A sits 1 meter away from B.

Step 3: B opens the solution (e.g. the perfume) and starts the stopwatch. When A smells the solution, B stops the watch and records the time it took to travel through the air. Repeat the procedure with the same solution and work out the average time taken.

Step 4: Repeat step 3 with all the other solutions, testing each smell twice.

Results from Group 3:

Solution Time Taken (a) Time Taken (b) Average Time Taken
Vanilla essence 35 seconds 20 seconds 27.5 seconds
Perfume 12 seconds 15 seconds 13.5 seconds
Vinegar 14 seconds 11 seconds 12.5 seconds 

What we learned:

We learned that gases have different properties.

Experiment 4: How much salt will dissolve?

Equipment: Salt, a plastic teaspoon, warm/cold water, a jar, a thermometer

Method:

Step 1: With the help of an adult, mix hot and cold water in a jar so that it reads 20 degrees on the thermometer.

Step 2: Stir in the salt one teaspoon at a time. Ensure you wait for one teaspoon to fully dissolve before you add the next one. Record how many teaspoons of salt you have added into the jar before it stops dissolving.

Step 3: Repeat this at 30 degrees, 40 degrees and 50 degrees. Record your results.

Results from Group 4:

Temperature of Water How much salt could be stirred in (teaspoons)
20 degrees 4
30 degrees 4
40 degrees 6
50 degrees 6

What we learned:

When the water is hotter, it dissolves more easily. Also, when a solid is added to a liquid eventually no more will dissolve.

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