YEARS 7–12 IDEAS FOR THE CLASSROOM
Year 7 Practical Skills for Inquiry Learning – Part 3 (continued)
– What one thing can you change to make the lid pop off
more quickly (or slowly)? Could you change something
else instead? You might even be more adventurous and
suggest a time frame e.g. after 10 seconds ..... . We are
not aiming to get into rates of reaction here! – but it does
lead to this line of inquiry, promotes problem solving and
the investigation of variables and controls – and having fun!
The discussion with the class as groups present their ideas
can bring out valuable suggestions and add to students’
confidence.
• There may be other questions, such as:
– What happens to the solids? (react and dissolve – mostly)
– Is the water still water? (no! – a reaction has taken place)
– proof? – (e.g. test with litmus, though you will need to
introduce this to them)
– Or any other suitable questions, which you can deal with
by letting the students work out what they need to do to
answer them.
• Again, we are working on the students investigative skills.
Scientific method (parts or all); need for evidence; tests to
provide this ... draw these out from the students as they are
working and as they share information.
– What gas do you think it is which causes the fizz? (– only
after they have told you that a gas is formed). If you
tell the students the names of the 3 ingredients, sodium
bicarbonate may trigger the suggestion that carbon
dioxide is the gas. Oxygen may be another suggestion, or
hydrogen – but whatever does come up the next question
must be:-
• Keep an eye on practical skills, co-op group skills etc. as they
are working – once having learned a skill they should always
use it ‘correctly’.
• As always – share ideas. Perhaps put together groups which
answered the same questions first and then let the enlarged
groups share with the rest of the class. Remember to try to
get the groups to be explicit about the steps they have taken
to answer their chosen question and to explain the thinking
behind these steps.
• How can you check? (they need to say that they need to test
it to prove the identity. The gas is CO 2 and you can then tell
them the lime water test – see diagram below for a simple
way to do this using a Pasteur pipette. If they suggest another
gas – let them test for it as long as it is possible to do simply –
you will need to tell them the appropriate test. This of course
is the same gas which caused the fizz in the previous activity
“Sherbet Fizz’.
We are getting very close to formalising the processes of the
‘Scientific Method’, but still I would not introduce the terminology
just yet. The activity ‘Bubbles!’ in Part 4 gives the opportunity to
do this.
• If the suggestion is oxygen (relights a glowing splint) or
hydrogen (puts out a lighted splint with a ‘pop’) when students
try this the splint will be extinguished, which could indicate
the gas is carbon dioxide. However, this is not a proof for CO 2
since most gases will do it as well, so the lime water test is
needed to confirm. Different groups may want to test different
gases, but ultimately all will need to come round to CO 2 .
Questions
Questioning skills are integral to an inquiry-based approach
to teaching and learning in science. They are also of great
importance to other approaches, as the ability of students to ask
questions and find answers to meaningful questions underpins
their true understanding of science ideas. Therefore we need to
help and encourage students to develop their questioning skills
and there are a couple of ideas listed below – I am sure you will
know of many more.
Most of these ideas come from the Project for Enhancing Effective
Learning (PEEL) which contains a huge list of teaching activities
which teachers in PEEL schools have come up with to try to
counteract the ‘poor learning behaviours’ of students.
1. Fat (or Rich) and Skinny Questions
* It is important for teachers to ask mainly ‘Fat’ rather than ‘Skinny’
questions of their students, as these require students to think
more deeply about their answers.
Use the pipette to transfer the gas from above the
reaction mixture and bubble it into the lime water.
You need to do this several times and the lime water
will go milky.
Fat (or Rich) questions are those which encourage the student to
think about the answer rather than simply recall it (thin or skinny
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SCIENCE EDUCATIONAL NEWS VOL 68 NO 3