Basic 9 · Science · Term Preparation

Preparing for the Term in Science

In this topic you will prepare for the term by recalling key ideas in science, reviewing investigative skills and planning how you will observe, investigate, record and present findings.

By the end of these notes you should be able to:

Recall key ideas in science from Basic 8
Apply science process skills
Plan and record a simple investigation

What you already know

Science, Basic 8

Copy everything that has a blue line on its left into your notebook. The other parts are for reading.

Lesson 1

Strand: Diversity Of Matter
Sub-strand: Term Preparation

Introduction

The B.E.C.E. tests what you have learned across all your junior high school years. A good review now will pay off later.

1. The Five Themes

Themes in Science

Theme	Examples
diversity of matter	elements, compounds, cells
cycles	nitrogen, carbon, life cycles
systems	body systems
forces and energy	energy, electricity, motion
humans and the environment	health, conservation

2. Ideas to Recall

Review of ideas

Topic	Key point
atoms	the smallest particles of an element
elements	contain one type of atom
compounds	atoms chemically combined
mixtures	physically combined
cells	the basic units of life
energy	cannot be created or destroyed

Each new topic builds on these ideas. This term you will study how atoms form compounds, what makes a substance an acid or a base, and how cells are specialised for different jobs. You will also investigate the nitrogen cycle, the grasshopper's life cycle, the heart and the lungs, and how to calculate electricity use. Check that you understand the basics before you continue.

Students doing a science practical

Figure 1: Science practical List three science topics you find difficult.

3. Science Around You

Science is not only in the laboratory. Soap making, cooking and rusting are all chemistry. Your body is a working example of biology. A bicycle, a torch and a solar panel show physics. When you ask why something happens and how it could be tested, you are thinking like a scientist. Keep a notebook of questions, and try to find answers through observation and reading.

4. Preparing for the B.E.C.E.

Science papers test facts, understanding and practical skills. Learn definitions exactly, and practise drawing and labelling diagrams. Note the units used for every quantity. Practise answering questions on experiments, because you may be asked to describe the apparatus, method and observations. Start early, revise regularly and ask your teacher about anything that is unclear.

New words

atom: The smallest particle of an element.
element: A substance with one type of atom.
compound: Atoms chemically combined.
cell: The basic unit of life.

Summary

Science has five main themes.
This term builds on atoms, cells and energy.
Practise diagrams, definitions and experiments.

Class activity: Concept Map

Write "matter" in the centre of a page.
Link it to elements, compounds and mixtures.
Add examples.

You need: Beaker, Hand lens, Safety goggles

Exercises

Answer in your exercise book first, then check your answers.

1. The basic unit of life is the…
- A. cell
- B. atom
- C. rock
- D. organ
Show answer
Answer: cellBiology.
2. A substance with one type of atom is…
- A. an element
- B. a compound
- C. a mixture
- D. a solution
Show answer
Answer: an elementChemistry.
3. Energy cannot be destroyed.
- A. True
- B. False
Show answer
Answer: TrueConservation.
4. Atoms chemically combined form a ______.
Show answer
Answer: compoundChemistry.
5. Give the difference between a mixture and a compound.
Show answer
Answer: Mixtures are physically combined, and compounds are chemically joined.Comparison.
6. Name one example each of chemistry and physics in daily life.
Show answer
Answer: Soap making and a solar panel.Examples.

Lesson 2

Strand: Diversity Of Matter
Sub-strand: Term Preparation

Introduction

Knowing facts is only part of science. The other part is finding things out.

1. Process Skills

Process skills

Skill	Example
observing	noting a colour change
hypothesising	suggesting why it happened
controlling variables	keeping conditions the same
measuring	using a thermometer
recording	writing results in a table
inferring	explaining results

2. Variables

Types of variables

Variable	Meaning	Example: testing plant growth with light
independent	what you change	amount of light
dependent	what you measure	height of plant
controlled	what you keep the same	water, soil, plant type

A fair test changes one variable only. If you change the light and the water together, you cannot say which of them caused the result. Repeating a test makes the results more reliable.

Hypothesis

Write a hypothesis on salt and the boiling point of water, and name the variables.

Hypothesis: adding salt raises the boiling point of water.
Independent variable: the amount of salt.
Dependent variable: the boiling temperature.
Controlled variables: the amount of water and the heat source.

Answer: A testable hypothesis with three kinds of variable

A thermometer in a beaker of water

Figure 2: Measuring temperature Plan a fair test on a question of your own.

3. Accuracy and Reliability

Accuracy means being close to the true value. Reliability means getting the same result when a test is repeated. Good scientists use suitable instruments, read scales at eye level and repeat readings. Keep your observations honest. A result that does not match your hypothesis is still useful, and it may lead you to a better one.

4. Safety Reminder

Follow the rules of the laboratory. Wear protective clothing when required, and tie back long hair. Do not taste chemicals. Treat all substances as if they could be dangerous. Know where the first aid kit and fire extinguisher are kept. Report every accident.

New words

hypothesis: A testable suggested explanation.
variable: A factor that can change.
reliable: Giving similar results when repeated.
inference: A conclusion based on evidence.

Summary

Process skills are ways of finding things out.
A fair test changes one variable.
Good results are accurate and reliable.

Class activity: Variables Table

Choose a simple investigation.
Identify the three kinds of variable.
Share your table.

You need: Beaker, Hand lens, Safety goggles

Exercises

Answer in your exercise book first, then check your answers.

1. What you change in a test is the…
- A. independent variable
- B. dependent variable
- C. result
- D. conclusion
Show answer
Answer: independent variableVariable.
2. Reliability means…
- A. similar results when repeated
- B. a big result
- C. a costly test
- D. no results
Show answer
Answer: similar results when repeatedTerm.
3. A fair test changes one variable at a time.
- A. True
- B. False
Show answer
Answer: TrueRule.
4. A testable suggested explanation is a ______.
Show answer
Answer: hypothesisTerm.
5. Name three process skills.
Show answer
Answer: Observing, measuring and recording.Any three.
6. Why is a result that disproves a hypothesis useful?
Show answer
Answer: It shows that the idea was wrong and leads to a better one.Science.

Lesson 3

Strand: Diversity Of Matter
Sub-strand: Term Preparation

Introduction

Scientists share their work so that others can check it and build on it.

1. Parts of a Report

Sections of a science report

Section	Content
title	what was studied
aim	the purpose
hypothesis	what you expect
materials	apparatus used
method	steps taken
results	tables and graphs
discussion	what results mean
conclusion	the answer to the aim

2. Tables and Graphs

Result tables should have headings and units. Line graphs show how one variable changes with another, with the independent variable on the horizontal axis. Bar charts compare categories. Draw graphs in pencil on graph paper, and choose a scale that uses most of the paper. Plot points carefully, and draw a smooth line of best fit.

Reading a graph

A plant's height is 2 cm on day 1, 4 cm on day 3, and 6 cm on day 5. Predict the height on day 7.

Height rises by 2 cm every 2 days.
From day 5 to day 7 is 2 days.
6 + 2.

Answer: 8 cm

A student drawing a graph

Figure 3: Drawing a graph Draw a graph of plant height over time.

3. Scientific Diagrams

Diagrams in science are simple line drawings. They are not works of art. Use a sharp pencil, and do not shade them. Draw straight label lines with a ruler, and do not let them cross. Give the diagram a title, and write the labels horizontally. In examinations, marks are given for accuracy, labels and clear lines.

4. Presenting Findings

Share your findings in a clear way. Begin with your question, describe your method and show your results. Explain what they mean. Be honest about what could have gone wrong. Accept questions, for this is how science improves. Many Ghanaian scientists present at conferences, and the Ghana Academy of Arts and Sciences helps to promote their work. You can begin to practise the same skills in your classroom.

New words

aim: The purpose of an investigation.
axis: A reference line on a graph.
line of best fit: A line showing the trend in data.
label: A word naming part of a diagram.

Summary

Reports have a clear structure.
Graphs show trends, and diagrams must be neat.
Present findings honestly.

Class activity: Mini Report

Carry out a simple experiment.
Write a report with a table.
Present it to the class.

You need: Beaker, Hand lens, Safety goggles

Exercises

Answer in your exercise book first, then check your answers.

1. Which section gives the steps?
- A. method
- B. title
- C. aim
- D. hypothesis
Show answer
Answer: methodReport.
2. Label lines should be drawn…
- A. with a ruler
- B. freehand
- C. in colour
- D. crossing each other
Show answer
Answer: with a rulerDiagram.
3. Scientific diagrams should be shaded.
- A. True
- B. False
Show answer
Answer: FalseSimple line drawings.
4. A line showing the trend in data is the line of best ______.
Show answer
Answer: fitGraph.
5. Give four sections of a report.
Show answer
Answer: Aim, method, results and conclusion.Any four.
6. Which axis should show the independent variable?
Show answer
Answer: The horizontal axis.Graph.

Homework

Write a report of a simple experiment at home.