ACID RAIN SCORING 2
Any one of car exhausts, factory emissions, burning fossil fuels such as oil and coal, gases from volcanoes or other similar things.
Burning coal and gas.
Oxides in the air come from pollution from factories and industries.
Fumes from power plants. [«Power plants» is taken to include power plants that burn fossil fuels.]
They come from the burning of materials that contain sulfur and nitrogen.
Responses that include an incorrect as well as a correct source of the pollution.
Fossil fuel and nuclear power plants. [Nuclear power plants are not a source of acid rain.]
The oxides come from the ozone, atmosphere and meteors coming toward Earth. Also the burning of fossil fuels.
Responses that refer to «pollution» but do not give a source of pollution that is a significant cause of acid rain.
The environment in general, the atmosphere we live in – e.g., pollution.
Gasification, pollution, fires, cigarettes. [It is not clear what is meant by «gasification»; «fires» is not specific enough; cigarette smoke is not a significant cause of acid rain.]
Pollution such as from nuclear power plants.
Scoring Comment: Just mentioning «pollution» is sufficient for Code 1. Any accompanying examples are only assessed to see if the response merits Code 2 instead.
Other responses, including responses that do not mention «pollution» and do not give a significant cause of acid rain.
They are emitted from plastics.
They are natural components of air.
Coal and oil. [Not specific enough – no reference to «burning».]
Nuclear power plants.
Industrial waste. [Not specific enough.]
ACID RAIN SCORING 5
To compare with the test of vinegar and marble and so show that the acid (vinegar) is necessary for the reaction.
To make sure that rainwater must be acidic like acid rain to cause this reaction.
To see whether there are other reasons for the holes in the marble chips.
Because it shows that the marble chips dont just react with any fluid since water is neutral.
To compare with the test of vinegar and marble, but it is not made clear that this is being done to show that the acid (vinegar) is necessary for the reaction.
To compare with the other test tube.
To see whether the marble chip changes in pure water.
The students included this step to show what happens when it rains normally on the marble.
Because distilled water is not acid.
To act as a control.
To see the difference between normal water and acidic water (vinegar).
To show the distilled water wasnt an acid.
SUNSCREENS SCORING 5
A. With explanation that the ZnO spot has stayed dark grey (because it blocks sunlight) and the M spot has gone white (because mineral oil absorbs very little sunlight).
[It is not necessary (though it is sufficient) to include the further explanations that are shown in parentheses.]
A. ZnO has blocked the sunlight as it should and M has let it through.
I chose A because the mineral oil needs to be the lightest shade while the zinc oxide is the darkest.
A. Gives a correct explanation for either the ZnO spot or the M spot, but not both, and does not give an incorrect explanation for the other spot.
A. Mineral oil provides the lowest resistance against UVL. So with other substances the paper would not be white.
A. Zinc oxide absorbs practically all rays and the diagram shows this.
A because ZnO blocks the light and M absorbs it.
B. ZnO blocks the sunlight and mineral oil lets it through.