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P4 -7 Science experiments

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On Monday primary 4-7 undertook various experiments about ‘changes’ as this is our topic this term.  Here are some of our experiments:

We have placed a white flower into water, with food colouring added in, to see if this changes the colour of the petals. Flowers absorb water through the xylem, which is a tissue of thin tubes found inside the stem. Water is transported to the various parts of the plant including the flower. Because the water is coloured the petals should then take on the colour.

It has been 2 days and the flower in the green water has begun to turn green but there isn’t much change with the other flowers yet. Some of us thought the flower would change within: 5 minutes, 20 minutes, 1 hour or 1 day but we were all wrong with our hypothesis.

We split the stem of a rose into 3 and placed each of these in a different colour, red, blue and yellow, to see if this will give us a rainbow rose.

This hasn’t really changed yet but we know with the other flowers that it could take a while.

 

We placed eggs into different liquids to see if/how this changes the egg. We have one in water as a control, one is in coke, another in vinegar and the last in fresh orange juice. We discussed our hypothesis on what we thought would happen to each egg:

  • The water wouldn’t change the egg
  • The coke would dissolve the shell and make it bounce
  • The orange juice wouldn’t do anything
  • Some thought the vinegar would dissolve the shell and make it bouncy

As soon as we put the egg in the vinegar it started to react by producing lots of bubbles, this is because the calcium carbonate in the shell is dissolved by the acetic acid producing carbon dioxide.

We checked the eggs after 1 day and there were slight changes:

  • The water had cracked the egg and it began to seep out
  • The coke hadn’t dissolved very little
  • The orange juice had dissolved quite a lot which was surprising
  • The vinegar had dissolved lots and made the egg squishy and bouncy

We checked the eggs again today and it was very interesting:

  • The water hadn’t changed from the day before, it was still split but nothing more has come out
  • The coke had dissolved very little but had stained the egg further
  • The orange juice dissolved the shell a little more
  • The vinegar had made the egg even bigger and bouncier

Below are close ups of the control, orange juice and coke

As you can see the egg in the vinegar is much bigger than the control egg in the water. This is because the membrane around the egg is semi permeable. Whilst it was in the vinegar the liquid moved through the membrane into the egg resulting in the membrane swelling and increasing in size.

We tested how well the vinegar egg could bounce. It bounced from 10cm high so we went up to 20cm and it still bounced so we tried dropping it from 30cm…it didn’t bounce though.

 

We poured milk into a glass and added red bull. When we discussed what we thought would happen there were a few different thoughts:

  • it would curdle
  • it would separate
  • it would sink to the bottom

You can just about see from the photo there is a layer at the top of the glass. After 5 minutes of pouring in the red bull the acid in the Red Bull causes the protein  in the milk to separate. When the milk curdles, a chemical reaction takes place resulting in a precipitate.

 

We did one more experiment with milk. We placed enough milk on a plate to cover the bottom. Then we poured drops of food colouring into the milk but nothing happened. We then took a cocktail stick and placed one end in fairy liquid before placing this into the milk and food colouring. What happened next was really cool.

The colours began to spread away from the fairy liquid and began mixing together. This is because fat and protein molecules in the milk are altered by the soap. These fat and proteins are super sensitive to change in the milk so when the fairy liquid is added it creates a chemical reaction and causes them to roll around. Once the soap molecules have mixed evenly with the fat and protein molecules the motion stops so we added more fairy liquid to keep the action moving. The food colouring helps us to see this change.

 

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P4-7 Topic

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This term we have been looking at the topic ‘Changes’. We have learned about climate change and changes in the body.

We have learned about drugs and the effect of this on the body as these can change the people who use them in all kinds of ways: they can make you happy, angry, upset, sad, scared, excited, tired or paranoid. They can stop your body working if they are taken too much or for too long, especially the brain, lungs and liver. We looked at what legal and illegal drugs are and that drugs are harmful if they are used inappropriately, incorrectly or excessively. Here is what we have learned:

A drug is any substance which causes a change in the way the body, or part of the body work.

Illegal drugs are drugs that are against the law to carry, take or sell. Some are illegal because they can be really harmful or be addictive. They are sorted into different classes: Class A drugs are things like heroin and cocaine – these are the worst drugs and most harmful, there are class B and Class C drugs too.

Legal drugs are drugs that are prescribed to you by a doctor or bought over the counter which help you and your body, we call these medicines, or they have an age limit on them, like alcohol and tobacco products.  Coffee, tea, coca-cola, energy drinks and chocolate all contain caffeine which is also a legal drug. Caffeine is a mild stimulant which can make us feel more awake, but if we take too much it can make us irritable and give us headaches. The drug in tobacco is called nicotine which is addictive – we are going to learn more about smoking next week when the health visitor comes in to talk to us.

Alcohol can also be addictive and affects your body as it changes the way you think and feel. Addiction is when something becomes a habit and is hard to break. Some people feel they need these ‘drugs’ to help them as they are dependent on them and can feel sick if they don’t have them. There are lots of different organisations that can help people with addiction. The AA (alcoholics anonymous) is one for people who are affected by alcohol, it might be the person themselves or their families. It gives them a chance to share their experiences and see/speak with others, they try to support each other to recover.

It is illegal to sell alcohol or tobacco to anyone under the age of 18! The government recommends that pregnant women do not drink as this could harm the baby.

Alcohol relaxes you and reduces tension but it does lead to poor concentration, slow reflexes/reaction time, reduces coordination, slurs you speech, makes you sleepy, affects your emotions/vision, make you sick or pass out.

Primary 4 and 5 created posters on the short term and long term effects that alcohol have on your body.

Short term risks usually linked to drunkenness are head injuries, fractures, facial injuries and scarring. They can also include alcohol poising.

Long term risks can include: liver damage, stomach ulcers, increased blood pressure which can cause heart disease/heart attacks or strokes, male sperm production decreases and it disrupts normal brain development.