Any video from this channel has a great experiment, which I can use to get the students to write a procedure, as each step is printed on the screen. The demonstrator also emphasises safety and spells out how he is doing the experiment.
So, at the start of year 7 your students should be able to write a procedure from a source such as this then hopefully discuss what happened.
I do use examples that allow me to talk about the science, such as density, air pressure or solubility but if you used an example like this one K-6 , just to discuss variables and fair tests as per your syllabus:
1. Students watch youtube to write a procedure, using numbered steps and correct text type
2. students discuss what experiment they could test based on this experiment, perhaps give them the equipment you have such as 2 liquids and corn.
You could get some great discussion to get students to make up their own hypothesis. Then I'm sure you get them to suggest one experiment such as that the corn kernel will float in the maple syrup by not water.
3. Students write one hypothesis eg corn will float is thick liquids ( like maple syrup) but not thinner liquids (like water)
Now you have the basis of an investigation, because you can change ONE THING ie the liquid the corn gets floated in and test one thing.
To a scientist the one one you changed is the independent variable .
You test what floated so this is called the dependent variable.
So "Does the kernel float?" Your answer depends on the liquid tested.
Now what do we keep the same ?? The temperatures of the liquid, the amount of shaking, not stirring it. This is all about doing a FAIR TEST. so brain storm "How could we cheat??" Deliberately mix one? Change the size of the corn, or use 2 different objects? Students should realise that to be a fair test they have to treat each test the same except for the one thing they are deliberately changing.
3. Identify the variables you would have to keep the same to do a fair test.
4. What one thing are you changing and what are you testing?
This is what we would have in year 7:
Aim: to see which liquid the corn kernel will float in.
Hypothesis the corn will float in thicker liquid like maple syrup but not thinner liquid like water
Method 1. Get 100ml of each liquid in a beaker
2. Carefully place one corn kernel on the top of the liquid to see if it floats
Controlled variables; size of corn, amount of liquid, temperature of liquid, no amount of stirring.
table of results
Relating to syllabus;
Let's say you did this kind of experiment with your students at this stage, here what I think you'd end up with, just looking at one lot of outcomes.
• show that equipment should be used with care and safety. ie wash hands after, don't eat etc
• state the purpose of an investigation. To see what liquids the corn will float in
• give examples of the ways the different senses can be used in observing. using eyes, perhaps also need magnifying glass• recognise that discoveries can be made through play, exploring and experimenting. experiment as shown on youtube and their simple version
• demonstrate that tools and equipment can be used to aid observation. measuring height of liquid in a cup eg 2cm so its all the same
get students to try to repeat part of the experiment with 2 liquids and corn, perhaps modifying design so the corn floats, using pencils etc to help make the corn floatStage Two
• demonstrate that investigation can take many forms. ie testing floating
• recognise that the results of investigations can lead to more questions. ie why does it not float in water.
• show that designing and making can lead to the need for investigations.ie fair test
• give examples of predictions that are sometimes supported, sometimes disproved.
Write a prediction such as which liquid the corn will float in, or other liquids that it could float in.
• recognise that investigations may be conclusive/inconclusive. test other liquids, or it doesn't always work
• describe the social, environmental or economic implications of the investigation of new materials and processes. Such as using floatation in industry eg mining
• identify investigations which involve discoveries leading to unexpected outcomes. possible use of this??
• show some relationship between the process of investigation and the process of designing and making. the need to change design if corn always sinks
• describe the process of investigation which can involve exploring and discovering phenomena and events, proposing explanations, initiating investigations, predicting outcomes, testing, modifying and applying understanding.
keep a journal of how they changed the stimulus material to what they actually did in class
And looking at the other outcomes, you can see that there could easily be scope to meet those outcomes using this or similar experiment.
For instance this for stage 3
• make detailed observations using appropriate technologies. photos, using a ruler to measure height of corn
• discuss the factors that might affect an investigation.ie control variables
• devise fair tests. is follow correct scientific procedure!!!
• identify data which support a particular prediction.results , hopefully in a table
• devise a test that will support or disprove a prediction.experiment
• modify and apply their understanding in the light of their investigation. What they conclude about their experiment