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Scientific Enquiry - Asking scientific questions

Grade 3IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

A scientific question is a question that can be answered by observing, measuring, or performing an experiment.

Scientists use their five senses to make observations about the world around them, such as noticing that H2OH_2O (water) changes state when heated.

A 'testable' question often follows a specific pattern, such as: 'How does changing XX affect YY?'

In a Fair Test, we only change one variable at a time while keeping everything else the same (constant).

Scientific questions often involve measurements of physical quantities like length (ll), mass (mm), time (tt), or temperature (TT).

A prediction is a sensible guess of what might happen in an experiment, based on what you already know.

📐Formulae

Fair Test=One variable changed+All other variables constant\text{Fair Test} = \text{One variable changed} + \text{All other variables constant}

1 cm=10 mm1 \text{ cm} = 10 \text{ mm}

Tboiling water=100CT_{\text{boiling water}} = 100^\circ\text{C}

Result=Observation+Measurement\text{Result} = \text{Observation} + \text{Measurement}

💡Examples

Problem 1:

Which of the following is a better scientific question for an experiment: 'Do plants like music?' or 'Does a plant grow taller if it is given 100 ml100\text{ ml} of water instead of 50 ml50\text{ ml}?'

Solution:

The second question: 'Does a plant grow taller if it is given 100 ml100\text{ ml} of water instead of 50 ml50\text{ ml}?'

Explanation:

This is a scientific question because it is 'testable'. You can measure the height of the plant in cmcm and control the amount of H2OH_2O provided.

Problem 2:

If you are testing which ball bounces the highest, and you drop Ball A from 100 cm100\text{ cm} and Ball B from 50 cm50\text{ cm}, is this a fair test?

Solution:

No, it is not a fair test.

Explanation:

To make it a fair test, you must keep the drop height (hh) the same for both balls. If h1=100 cmh_1 = 100\text{ cm} and h2=50 cmh_2 = 50\text{ cm}, you are changing two things at once: the type of ball and the height.

Problem 3:

A student wants to know how temperature affects the time it takes for sugar to dissolve. Identify the variable to be measured.

Solution:

The time tt in seconds or minutes.

Explanation:

The student is changing the temperature (TT) to see how it affects the speed of dissolving, which is recorded as the time (tt) elapsed.