Scientific communication

A scientific report has these sections, but they are out of order: conclusions, aim and hypothesis, results, equipment and procedure. Put them in order and write one sentence about what is included in each section.

State which section of the report each sentence belongs to:

1. a) "We used two beakers, a measuring cylinder, a thermometer and a stopwatch."
2. b) "The salt dissolved faster in hot water."
3. c) "We wanted to test whether water temperature affects the dissolving of salt."
4. d) "The results support our initial hypothesis."

A table reads: after $1$ minute there is $10\ \text{g}$ of dissolved salt; after $2$ minutes, $20\ \text{g}$; and after $3$ minutes, $30\ \text{g}$. Write a one- or two-sentence conclusion summarizing what happens.

Convert these notes into the results section of a report, written in two or three complete sentences: "puddle in the sun: dries in $25$ minutes; puddle in the shade: dries in $60$ minutes".

In an experiment, the hypothesis was: "a drink can cools down faster in ice than in the fridge". The data (both cans start at the same temperature): in ice it drops to $10\ ^\circ\text{C}$ in $15$ minutes; in the fridge, in $40$ minutes. Write the conclusions section: state whether the hypothesis is confirmed, support your answer with the data, and explain the result in one sentence.

A report has the objective ("check if light affects seed germination"), the hypothesis ("seeds germinate faster in the light"), and the results (in the light they germinated in $4$ days; in the dark, in $7$ days).

1. a) Write the conclusions section.
2. b) State what other important section is missing from the report and what it should include.

Scientists publish their experiments by describing the procedure in full detail: quantities, units, and steps followed.

1. a) Explain why they do this, considering other teams that might want to repeat the experiment.
2. b) What problems would a report have if it only said "we added a little salt and heated for a while"? Give two specific examples of missing information.

Unit challenge. Become a researcher and solve this challenge at home: does the oscillation period of a pendulum depend on its length?

1. Observation and hypothesis: Observe how a suspended object oscillates. Formulate a testable hypothesis and identify household materials equivalent to laboratory equipment (string, a nut as a mass), defining a basic safety rule to prevent accidents.

2. Experimentation and measurement: Build your pendulum. Always using the same nut and releasing it without pushing from a small angle (about $10^\circ$), the same in every trial, measure the time it takes to complete $10$ oscillations for three different lengths, measured from the suspension point to the centre of the nut ($0.20\text{ m}$, $0.40\text{ m}$, and $0.60\text{ m}$), repeating each trial three times. Record the uncertainty of your instruments (ruler: $\pm 0.1\text{ cm}$; stopwatch: $\pm 0.2\text{ s}$).

3. Communication of results: Prepare a brief scientific report that includes:

4. A data table with measured values, means, and uncertainties, calculating the period $T$.

5. A scatter plot ($T$ versus length).

6. A reasoned conclusion confirming or refuting your initial hypothesis.

Assessment criteria:

• Clear formulation of the hypothesis and application of safety rules with household materials.

• Rigour in taking measurements, repeating trials, and correctly expressing uncertainties.

• Quality of the scientific report, accuracy of the table, well-drawn graph, and coherent conclusions.

Aitana heats water and records the temperature every minute: at minute $0$, $20\ ^\circ\text{C}$; at minute $1$, $30\ ^\circ\text{C}$; at minute $2$, $40\ ^\circ\text{C}$; and at minute $3$, $50\ ^\circ\text{C}$.

1. a) What was the temperature of the water at minute $2$?
2. b) How much does the temperature increase each minute?

In a report table, the first column is titled simply "time" and the second simply "temperature". Rewrite both headings as they should appear in a scientific report, with the quantity and unit in brackets.

In an experiment on dissolving sugar, the following unordered data was obtained: at $40\ ^\circ\text{C}$ it takes $20\ \text{s}$; at $20\ ^\circ\text{C}$ it takes $60\ \text{s}$; at $60\ ^\circ\text{C}$ it takes $10\ \text{s}$. Organise them in a two-column table and write the heading for each column showing its quantity and unit.

A classmate hands in this table from a water heating experiment: the first column reads "time ($\text{min}$)" with values $0$, $5$ and $10$, and the second reads simply "temperature" with values $20$, $35$ and $50$.

1. a) What is missing from the second column heading?
2. b) Why is this mistake important?
3. c) Rewrite the column heading correctly.

A graph shows the height of a sunflower during the first three weeks of its growth. Look at the graph:

1. a) How tall was the sunflower in week $2$?
2. b) How much did it grow between week $1$ and week $3$?

Explain in your own words the advantage of a data table and the advantage of a graph. Give an example of when you would use each.

List the three things every graph must have to be understandable: a title, the label of the horizontal axis (with its quantity and its unit) and the label of the vertical axis (with its quantity and its unit). Then, explain why drawing the line is not enough.

A graph shows how a cup of tea cools down: when poured it is at $70\ ^\circ\text{C}$; after $10$ minutes, at $50\ ^\circ\text{C}$; and after $20$ minutes, at $40\ ^\circ\text{C}$. Observe the graph:

1. a) How much did the temperature drop between minute $10$ and minute $20$?
2. b) Calculate how much it dropped in the first $10$ minutes and state in which of the two intervals it dropped more.

A graph shows the temperature of a glass of ice being heated: it rises from $-5\ ^\circ\text{C}$ to $0\ ^\circ\text{C}$, remains flat at $0\ ^\circ\text{C}$ for a while, and then rises again, as shown in the graph.

Interpret what is happening to the ice along the horizontal section and explain why the temperature does not rise there.

A distance-time graph of Aoife's bike ride has two sections: in the first section she covers $4\ \text{km}$ in $20$ minutes, and in the second, $6\ \text{km}$ in $20$ minutes. Observe the graph:

1. a) In which section was she travelling faster?
2. b) How can you tell from the graph? Think about the gradient of each section.

1. a) You want to compare the monthly rainfall in your town throughout the year.
2. b) You want to show how the temperature of an oven changed over one hour.

For each case, choose the most appropriate form of representation (table, bar chart or line graph) and justify your choice.

A graph compares how water cools down in a metal glass and in a plastic glass: the water in the metal glass drops from $60\ ^\circ\text{C}$ to $30\ ^\circ\text{C}$ in $10$ minutes; the water in the plastic glass drops from $60\ ^\circ\text{C}$ to $45\ ^\circ\text{C}$ in the same time. Look at the graph:

Write a three- or four-sentence analysis for the report: which one cools down faster, how this can be seen on the graph, and what conclusion you draw about the materials.

Here are the times for the $100\ \text{m}$ sprint of four friends: $14$, $16$, $15$ and $13$ seconds.

1. a) State the maximum and minimum values.
2. b) Who ran faster, the person with the maximum time or the minimum time? Explain why.

You want to see at a glance whether the swimming pool water heats up faster and faster throughout the day. What would you present: a table or a graph? Justify your choice.

A graph in a report has no title, the horizontal axis only says "time" without a unit, and the vertical axis has no label at all.

1. a) Point out all the mistakes.
2. b) Rewrite how that graph should be presented (full title and labels) if it shows how water is heated over $10$ minutes.
3. c) Explain the problem with interpreting a graph without units.

The weight table for a kitten reads: at $1$ month, $1\ \text{kg}$; at $2$ months, $2\ \text{kg}$; at $3$ months, $1.5\ \text{kg}$; and at $4$ months, $4\ \text{kg}$.

1. a) Which data point seems incorrect? Why?
2. b) Propose an explanation for how this error might have occurred.
3. c) What should the team do before drawing conclusions?

A dripping tap fills a glass very regularly: after the first hour there is $50\ \text{mL}$; after the second, $100\ \text{mL}$, and after the fourth, $200\ \text{mL}$.

1. a) Predict how much water there will be after $8$ hours.
2. b) Explain how you calculated it.
3. c) Is your prediction completely certain? Mention one thing that could cause it to fail.