Download PowerPoint 1.1 Understanding the Nano scale (9 slides

Some little questions
about big ideas
How can we begin to imagine measurements
smaller than we can see?
What units of measure are used that are smaller
than millimetres?
What issues might scientists have when working
at very small scales?
Smaller and smaller
• Take a single piece of graph paper and cut out
two 4cm x 4cm squares
• Cut one of the 4cm x 4cm exactly squares in
half
• Take one of the 4cm x 2cm rectangles and cut
it exactly in half
How many times do you think you could cut
could cut a “half” in half?
Little results
Number of cuts
0
1
2
3
4
5
6
7
Thickness in centimetres
More questions
• Could you continue cutting your “halves” in
half seven times or more?
• What issues did you have?
• How useful is a value less than 0.5?
• What is the first measurement smaller than a
millimetre?
• How do we convert units?
Units and conversion
• a millimetre is a thousandth of a metre
• a micrometre is a millionth of a metre
(a thousandth of a millimetre)
• a nanometre is a billionth of a metre
(a thousandth of a micrometre)
Units and conversion
The 6th cut in the paper halving activity would have
a width of 0.0625 cm.
0.0625 cm x 10 = 0.625 mm
0.625 mm x 1000 = 625 µm
625µm x 1000 = 625 000 nm
Extended results
• Thinking about the “halving” the half activity,
complete the following table.
Number of cuts
7
8
9
10
Width in cm
0.03125
Width in mm
Width in µm
Width in nm
More questions
How many “halving cuts” would it take to get
the strip of paper to be as thin as a stand of
hair?
How many “halving cuts” would it take to get
the strip of paper to be 10nm thick?
What issues can you now consider when
working at the nanoscale?