The last topic listed the ten parts of a report. This topic shows those parts being used together in three real examples, so you can see exactly what a finished report looks like. As you read each one, keep asking yourself which of the ten parts you are looking at, and notice that a short report does not always use all ten.

Why does that work? Air is a gas, and the tiny particles in a gas sit very far apart from one another with a lot of empty space between them. Squeezing the bottle simply pushes those particles closer together, and the same amount of air now fits into less space. Try the same thing with a bottle full of water and you will find it barely moves at all, because in a liquid the particles are already packed close together with almost no room left to squeeze out.

The important idea here is that the flame did not stop because it ran out of candle. There was plenty of candle left. It stopped because the one thing it needed from the air, oxygen, had been used up inside that sealed glass. Notice also how careful the wording of the conclusion is. It does not claim that air is oxygen, only that air contains oxygen mixed within it, because the flame burned for a while before going out rather than not burning at all.

Distillation works because of one simple difference between the two things being separated. Water turns into vapour when it is heated, but salt does not. So when the mixture boils, only the water leaves the flask, travelling away as vapour and abandoning the salt behind. The condenser then does the opposite job: cold water flowing around it cools the vapour back into liquid water, which drips out clean and free of salt. Two changes of state, evaporation and then condensation, are all that this whole apparatus is arranging.

Now look back at all three reports together and count the parts. Each one has an objective, materials, a procedure, an observation, a result, and a conclusion. That is six of the ten. Each also has a title and a figure, so eight. But none of the three includes an analysis, and none includes a precaution.

This is not a mistake in the textbook. Short sample reports are often trimmed to the parts that matter most for the point being made. But it is worth noticing, because it is exactly the kind of thing you should be able to spot now. The candle report in particular could use a precaution, since it involves a lit flame, and the paragraph above about oxygen being used up while candle wax remained is really an analysis that the sample report never wrote down. Being able to see what a report leaves out is a genuine skill, and it is the difference between reading a report and simply believing it.

Question 1 of 7