Year 8 Science · Unit 2 · Lesson 04
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Two words will not be used.
A scientific is a simplified used to explain, describe or things that are difficult to observe .
Put the atomic models in order
Number the models from 1 (oldest) to 5 (newest). Then write the year of each one, choosing from: 1911, 1803, 1932, 1897, 1913.
| Order (1–5) | Scientist and model | Year |
|---|---|---|
| Thomson: after discovering the electron, pictures electrons dotted through a positive sphere (the plum-pudding model). | ||
| Bohr: electrons move in fixed shells around the nucleus. | ||
| Dalton: the atom is a solid sphere that cannot be split. | ||
| Chadwick: discovers the neutron, so the nucleus holds protons and neutrons. | ||
| Rutherford: a tiny, dense nucleus at the centre, with most of the atom empty space. |
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. Scientists use models to explain, predict and communicate ideas.
Correct it:
2. A model must be 100% accurate, or it is useless.
Correct it:
3. We need models of atoms because atoms are too small to see, even with ordinary microscopes.
Correct it:
4. When a model is replaced, it shows that the scientists who made it did bad science.
Correct it:
5. A ball-and-stick kit shows exactly what a real molecule looks like.
Correct it:
Read the data
Checking a weather model
The Bureau of Meteorology uses computer models of the atmosphere to forecast the weather. A student recorded the forecast maximum temperature each morning for one week, then the real maximum that afternoon.
| Day | Forecast (°C) | Actual (°C) | Difference (°C) |
|---|---|---|---|
| Monday | 24 | 25 | |
| Tuesday | 27 | 26 | |
| Wednesday | 22 | 19 | |
| Thursday | 20 | 21 | |
| Friday | 25 | 25 |
Source: sample forecast log kept by a student.
1. Fill in the difference column. On which day was the forecast furthest from the actual temperature, and by how much?
2. The student concludes: “The forecast was wrong on four days out of five, so the weather model is useless.” Use the data to explain why this conclusion is weak.
3. A globe and a flat world map are both models of Earth, and both are wrong in some way. Explain why each one is still useful. For each model, give one thing it shows well and one thing it gets wrong, then say which you would choose for planning a car trip.
Fill the gap
model; representation; predict; directly. Not used: photograph, guess.
Put the atomic models in order
Reading down the table as printed: 2, 4, 1, 5, 3.
Years: Thomson 1897; Bohr 1913; Dalton 1803; Chadwick 1932; Rutherford 1911.
True or false
1. True. 2. False: models are simplified on purpose; a model is useful if it helps explain and predict the thing being studied. 3. True. 4. False: each model was the best explanation of the evidence at the time; it was replaced when new evidence appeared. 5. False: it is a physical model; real atoms are not coloured balls and bonds are not sticks.
Read the data
1. Differences: 1, 1, 3, 1, 0. Wednesday, by 3 °C. [2 marks: 1 column, 1 day and amount]
2. Four of the five forecasts were within 1 °C (Friday was exactly right), so the model was close almost every time; only Wednesday was off by more (3 °C). A model does not have to be exact to be useful: it still tells people what kind of day to plan for. [3 marks: 1 use of data, 1 close is still useful, 1 models are simplified, not exact]
Show What You Know
3. Marking guide: 1 globe strength (true shape of continents, Earth’s curve); 1 globe limitation (scale: cannot show mountains or roads in detail; too big to carry); 1 flat map strength (shows roads, easy to carry and use for navigation); 1 flat map limitation (Earth is not flat, so shapes and sizes are stretched); 1 choice with reason (a road map, because it shows the detail needed for that job). [5 marks]
Common error to watch for: in Q3, writing “it is wrong” as the limitation. Ask students to name what the model leaves out or shows incorrectly.