Lesson by Rachel Adams
Learning Intentions:
- To carry out a scientific experiment.
- To write up an experiment.
Step 1: Activity overview for parent, carers and pupils
This activity is completely offline.
Adult support will be required for the practical task.
Resources are needed such as lemon or lime juice, water, soy sauce, washing-up liquid, vinegar, coke, ketchup, salt water, chilli sauce, mustard, milk (choice of five), five pennies, and five containers / glasses.
The experiment will take at least 30 minutes.
Written work can be completed on paper.
Step 2: Introduction to the activity and additional information
Why do pennies turn brown?
To explore the effectiveness of various cleaning solutions in cleaning tarnished coins
Have you ever wondered why some pennies are shiny and some are dull? It’s not just dependent on how old the pennies are. Chemical reactions are responsible for the change in a penny’s appearance over time.
In this science experiment the activity will focus on using a chemical reaction to make pennies shine.
Try some different substances to see what would work best for you. Pick a variety of household substances from the options below, and see which is the most effective at cleaning the pennies. You can add some of your own if you wish.
Lemon or lime juice, soy sauce, washing-up liquid, vinegar, coke, ketchup, salt, chilli sauce, mustard, milk.
Step 3: Tasks to carry out for this activity
Activity 1: Prediction
- Choose five substances that you are going to use for your experiment.
- Predict which you think will work the best (get the pennies the cleanest) and why?
- Predict which you think will be the worst and why?
- Write your predictions down.
Activity 2: Experiment
- First fill some cups with a small amount of the different substances. (Same amount in each of both water and substance. Remember it needs to be a fair test.)
- Let the pennies soak for 30 minutes.
- Put the pennies on a paper towel to dry and wipe or scrub the penny clean.
- Rinse them with running water and set them on a towel to dry.
- Write about the experiment by answering the following questions:
- What did we want to find out?
- What equipment was used?
- What did we do?
- What happened?
- What were the results / findings?
- Were your predictions correct?
- What could we keep the same? (fair test)
- What could we change? (variables)
- What is your conclusion?
Once you have completed the task you can email anything you create (photos, documents, screenshots etc.) directly to your teacher or directly upload it to any of the available places in Step 5.
Step 4: Look over the success criteria for this activity:
Success criteria #1: I can make a sensible prediction.
Success criteria #2: I can carry out a scientific experiment ensuring it is a fair test.
Success criteria #3: I can write up the results of my experiment using appropriate scientific language.
Look at the learning intentions ‘how well do you think you have done?’
Step 5: Upload your work
Click on the relevant link below if you have any work to upload to your online areas