|
||||||||||||
|
|||||||||||||
| Questions/instructions: This activity
uses the computer.
|
|||||||||||||
| %
responses 2003 ('99) |
|||||||||||||
| y4
|
y8 |
||||||||||||
| During the shower the mirror steamed up. | |||||||||||||
| 1.
Why did the mirror steam up during the shower? [Shower puts water vapour into the air. This travels through room to mirror. Condenses on mirror when it hits cooler surface.] |
full
explanation – all 3 elements |
1
(0) |
4
(1) |
||||||||||
partial
explanation – 2 elements |
8
(5) |
25
(24) |
|||||||||||
vague
explanation |
43
(50) |
46
(48) |
|||||||||||
| 2.
If the mirror was not wiped dry, it would clear by itself. What would
happen to the water on the mirror? Prompt: Where would the water go? |
water
evaporates back into air |
20
(17) |
47
(45) |
||||||||||
| 3. You’ve probably had the same thing happen to you. You have a shower or bath and then find the mirror all steamed up. What could you do to stop the mirror steaming up? |
not marked |
• |
• |
||||||||||
4. Why would that work? |
|||||||||||||
Reduce
moisture in air – dehumidifier; open a door or window; extractor
fan: |
at
least one of these ideas, well explained |
14
(13) |
36 (31) |
||||||||||
one
idea without explanation |
10
(3) |
13
(16) |
|||||||||||
Heating
air so it will hold more moisture – heater, heat lamp: |
at
least one of these ideas, well explained |
1
(1) |
3
(0) |
||||||||||
one
idea without explanation |
2 (3) |
8
(4) |
|||||||||||
Preventing
moisture reaching mirrorsurface – barrier such as a towel on mirror: |
at
least one of these ideas, well explained |
29
(33) |
23
(31) |
||||||||||
one
idea without explanation |
9 (13) |
5
(9) |
|||||||||||
Chemical
solution to prevent watercondensing on mirror: |
mentioned
and explained |
0 (0) |
3 (0) |
||||||||||
mentioned
without explanation |
3
(1) |
3
(3) |
|||||||||||
Reducing
moisture in air by having colder shower: |
mentioned
and explained |
3
(7) |
6
(3) |
||||||||||
mentioned
without explanation |
5
(5) |
3
(7) |
|||||||||||
Total
score: |
6–13 |
0
(1) |
9
(4) |
||||||||||
4–5
|
15
(19) |
38
(39) |
|||||||||||
2–3
|
49
(43) |
38
(45) |
|||||||||||
0–1
|
36
(37) |
15
(12) |
|||||||||||
| Commentary This widely observed phenomenon was not well explained. About 30 percent more year 8 than year 4 students scored 4 or above. There was very little change, at either year level, between 1999 and 2003. |
|||||||||||||
 |
||