What is the best way to melt an ice cube?

This was the investigation that Year 2 classes did this week.

They decided that to make ice melt you need to heat it up.

The students had to think about where they would put ice cubes in the class to make them melt. There was also some equipment they could use.

They came up with:

• Under a light
• In the sun
• By the heater
• In someone's hands
• In some hot water
• On top of the hot water bottle
• Wrapped in a towel

First we put ice cubes into glass dishes. We had to make sure the ice was the same size so the test was fair.

Then we put each dish in a different place and patiently watched to see the ice melt.

Which one do you think melted the fastest?

In most classes the ice cube that melted the fastest was the one in someones hands or the one in the hot water.

We were surprised that the ice in someones hands melted faster than the heater. We think it was because our hands were touching the glass dish so it would heat up faster and pass the heat on to the ice. The hot water did the same because it was surrounding the dish.

More Chemical Reactions

INVISIBLE INK

To make an invisible ink you mix lemon juice with a few drops of water. Then you write on a piece of paper with a cotton bud. Leave the message to dry.

Now you are ready to read the message. Iron over the paper for a while until the message appears. The lemon juice will turn brown.

This happens because there is carbon in the lemon juice. When you heat the lemon juice with an iron the carbon starts to break down and turn brown.

You could send a secret message to your friend.

RUSTY WOOL
How do you quickly turn this steel wool rusty?

Today in science club we found out how. First you need to soak the steel wool in some vinegar. Next you squeeze out the vinegar and place the steel wool in a jar. Now poke a thermometer into the steel wool and put the lid on the jar.

We watched to see what happened to the temperature on the thermometer and notice that it went up from about 17 degrees C to 30 degrees C.
There was also some fog on the inside of the jar.

Last week we found out that if a chemical reaction gives off heat it is called and exothermic reaction. So this must be one.

We also noticed that the steel wool went rusty really quickly.

But what is reacting?

The vinegar removes any protective coating on the steel wool so the steel wool begins to rust. When something rusts it is actually a chemical reaction between the iron and the oxygen in the air. Steel wool is made of iron so it can rust. When rusting occurs heat energy is released.

Magical Mixtures

Exothermic Reactions
by Chelsea, Poppy and Andy

Today in science club we mixed water, baking soda and calcium chloride to make a chemical reaction. We put the two bases in a plastic bag and then put water in a container and mixed them together. The plastic bag filled up with air and it fizzed and foamed while it was producing gas. The plastic bag got really hot and made a sizzling sound. This is called an exothermic reaction because it produced heat. An exothermic reaction is used in heat packs and hand warmers.

Hot
by Jasmin and Caitlin

Today in science club we investigated chemical reactions. We put 1 teaspoon of baking soda and 1 teaspoon of calcium chloride in a bag then filled up half a film canister with water and put it in the plastic bag. But we didn't let it touch the powder. We sealed up the bag then shook it. The mixture foamed and fizzed and was hot in the corners and it burned my finger. It was an exothermic reaction.

Mystical Mixtures

by Billy and Jake

Today we investigated chemical reactions. We tested out 2 mixtures. One was an endothermic reaction and one was an exothermic reaction. The exothermic one was really hot and sticky and smooth. The endothermic was really cold and the bubbles vibrated in the bag.

Magical Mixture
by Eden and Harrisen

Today in science club we tested out different chemical reactions. The second magical mixture needed to have water, tartaric acid and baking soda. We put baking soda and tartaric acid into a bag and mixed them together. Next we poured water into it and all of a sudden it fizzed up and got really cold. It did this because when you put all the ingredients together it creates an endothermic reaction. An endothermic reaction absorbs heat so it feels cold.

Magic Chemicals Number 2

by Jacob and Josh

Today at science club we were investigating chemical reactions. First we had to mix baking soda and calcium chloride together. Then we poured water in the canister. We could not pur it in the bag or the experiment would be ruined. We then sealed up the bag tight other wise it might spill out. Once we sealed the bag we shook it. The water spilled out so then the chemicals reacted and it fizzed up. It fizzed up and puffed up with gas (we think it is carbon dioxide). The reaction was exothermic which means it got hot.

Magic Mixtures
by Morgan and Avilisha

Today at science club we made chemical reactions. We mixed baking soda with calcium chloride and water. They foamed and fizzed. When we felt it it was hot and sizzling. After 10 minutes it turned into a liquid. When it was hot it released a gas. The reaction was called exothermic. It felt like boiling water.

The instructions for the experiments are below.

Today I drank a solution!

And it was really yummy!!!!

Don't worry mums and dads - the solution we drank is really harmless. We were finding out about things that dissolve. When we put salt into a glass of water and stirred it around the salt seemed to disappear. But really it is still there - it has just dissolved. Dissolving means that the salt particles got so small that we couldn't see them anymore.

First we had to test lots of different things to see if they would dissolve or not. It took a lot of stirring and mixing. We had to work together and record our results.


We found out that sugar, drink powder and coffee dissolved but tea leaves, sand and flour did not.

Miss Harrison taught us 3 tricky new scientific words.
Solvent - this is the liquid part of the mixture
Solute - this is the thing that gets dissolved in the liquid
Solution - this is the mixture of the solvent and the solute.

Next we got to make a solution that we could drink - LEMONADE!

This is the recipe we used:
Lemonade

1. Squeeze the juice from 3 lemons into a bowl.
2. Add 2 cups of sugar.
3. Add 3 teaspoons of citric acid.
4. Add 1 litre of hot water.
5. Stir the mixture until the sugar has dissolved.
6. Pour some of the lemon syrup into a cup. Fill the cup with water.
7. Your lemonade is ready to drink.

Do you know which parts of the mixture are the solute and solvent? We do!

Solvent = water and lemon juice
Solute = sugar and citric acid

We even got to drink the Solution! Cheers.

Fun with lenses

Lenses are used in many ways such as: eye glasses, microscopes, projectors, cameras, our eyes, contact lenses, telescopes and magnifying glasses.

What is a lens?

A lens is a specially shaped piece of glass. When light hits hit the light is refracted. This means that the light changes direction slightly. When you view objects through a lens they may appear bigger, smaller, closer, further away or upside down.


This is a convex lens and it makes my eye look larger.


This is a concave lens and it makes my face look smaller.


If you use 2 magnifying glasses at once the image will be even bigger.


A simple telescope can be made out of 2 lenses. We tried using to convex lenses and the image appeared upside down. When we used a concave and convex lenses the image was the right way up.

Can light travel around corners?

This was the question that the Year 5 and 6 students were posed this week.

Our main focus for the lesson was to give evidence to support the answer to the question. The students needed to understand that as scientists they could say something but for people to believe them they need proof.

The students did 2 investigation to gather evidence to support their answer to the question.

This picture shows us testing where a beam of light goes. We found out that light can only go in a straight line. The light was mostly blocked by the card but some of the light traveled through the holes and we could see it come out the other end. The light did not travel around the card because we could see a shadow behind the card.

Here we are trying to make it look like a beam of light is shining through a book. But really we are reflecting the light around the book.

Using the evidence gathered we came to these conclusions:

• Light always travels in a straight line from its source until it hits something.
• When light hits something shiny it will reflect off in a straight line.
• Light can only go around corners if it is reflected.
  

How can you separate a mixure?

Our 5 year olds know what a mixture is. To make a mixture you have to mix together 2 or more different things. They made fruit salad by mixing together many different pieces of fruit. This mixture was easy to separate back into the different parts but for some mixtures this is not so easy.

Look at the different ways we found for separating mixtures.

Sorting


Sieving


Filtering