Grade 7 INTEGRATED SCIENCE Study Notes

What Is Physics?

Physics is the study of matter and its relation to energy. It looks at how things move, how forces act on objects, how heat travels, how light behaves, and how electricity flows.

Examples of Physics Concepts

• Slopes as simple machines — a slope (inclined plane) reduces the force needed to lift an object.
• Light — Physics explains how light travels, reflects off surfaces, and bends when passing between materials.
• Heat — Physics explains how heat moves through metals, air, and empty space.
• Electricity — Physics explains how current flows through a circuit and powers bulbs and fans.

Physics explains everyday things: why a kicked ball curves through the air, how a torch produces light, and why a metal spoon gets hot when stirred in soup.

What Is Chemistry?

Chemistry is the study of the composition, structure, and properties of matter, and the changes that matter undergoes. Chemistry asks two questions: What is this substance made of? and What happens to it when conditions change?

• Composition — what a substance is made of (e.g. water is made of hydrogen and oxygen).
• Properties — characteristics like colour, smell, whether it dissolves or burns.
• Changes — what happens when a substance reacts (e.g. iron rusting, a candle burning).

Chemistry is happening around you constantly — food cooking on a stove, a metal gate turning orange-brown with rust, soap lifting grease off your hands.

Examples of Chemistry Concepts

• Composition of air — air is a mixture of gases; Chemistry tells us what they are and how much of each is present.
• Properties of matter — whether a substance dissolves, burns, or reacts with water.
• Chemical changes — burning a candle, cooking food, and rusting iron all produce new substances.

What Is Biology?

Biology is the study of living things. It covers every organism — from the tiniest microorganism you cannot see with the naked eye, to the largest tree, to the human body. Every living thing around you — trees in the school compound, insects in the grass, bacteria in your gut — is part of what Biology studies.

Examples of Biology Concepts

• Invertebrates — animals without a backbone, such as insects, earthworms, and snails.
• Fungi — mushrooms and moulds are living things studied in Biology.
• Plants — how plants grow, make food from sunlight, and produce seeds.
• The human body — how you breathe, digest food, and fight infection.

Scientific Investigation — Strand Introduction

In Grade 4 to 6 you studied Science and Technology. In Grade 7, you begin a new learning area called Integrated Science. This strand — Scientific Investigation — introduces you to what Integrated Science is, why science matters in daily life, and how to work safely in a laboratory.

What Integrated Science Is

The word integrate means to combine one thing with another to form a whole. Integrated Science is a learning area that combines various branches of science into one subject. Because the branches are studied together, you can see how they connect — a single event in daily life often involves more than one branch at the same time.

The Three Components

Integrated Science has three components (branches). Each studies a different part of the world around you:

• Physics — the study of matter and its relation to energy.
• Chemistry — the study of the composition, structure, and properties of matter, and the changes that matter undergoes.
• Biology — the study of living things.

Every topic you studied in Science and Technology — the insects, the air, the simple machines — already had a home in one of these three branches. Integrated Science names those homes and shows how they fit together.

Topics You Know and Where They Belong

Topics you studied in Science and Technology already fit into the three components of Integrated Science:

Science in Agriculture

Agriculture is the growing of crops and rearing of animals for food. Science has made farming easier, more productive, and more sustainable in several ways:

• Better farming tools and machines — such as tractors, irrigation pumps, and pesticide sprayers — save farmers time and effort.
• Improved seeds developed through science are resistant to pests and diseases, helping farmers grow more food.
• New watering methods such as irrigation, and better pest and disease control, protect crops and increase yields.

The food on your plate — maize, vegetables, milk — reached you more reliably because of science in agriculture.

Science in Health

Science has made huge improvements in both human and animal health.

Human Health

• Science has led to the development of vaccines, medicines, and treatments that help people live longer, healthier lives.
• Research helps scientists understand how diseases spread and how to prevent or treat them.
• Medical instruments developed through science allow doctors to examine and treat patients:
  • Stethoscope — listens to heart and lung sounds.
  • Thermometer — measures body temperature.
  • Syringe — injects medicines or draws blood.
  • X-ray machine — shows bones inside the body without surgery.

Animal Health

• Science helps develop better medicines, vaccines, and animal feed to keep animals healthy.
• Some diseases can spread from animals to humans; science protects both by researching and preventing such diseases.

Science in Transportation

Science has made transportation faster, safer, and more efficient.

• New car technologies make vehicles use less fuel and reduce pollution.
• Electric vehicles, developed through science, run on electricity instead of fuel — they produce no exhaust fumes, helping protect the environment.

The shift from hand-pushed carts to electric buses is one of the clearest examples of how science has transformed transport in a single lifetime.

Science in Food

Science has improved how we produce, store, and keep food safe:

• Better processing, packaging, and preservation methods make food last longer and stay fresh.
• Science checks food for harmful bacteria and chemicals before it reaches consumers.

Packaged foods you see in shops — long-life milk, canned vegetables, vacuum-sealed biscuits — stay fresh because of food science.

Science in Textiles

Science has helped create better clothes and fabrics:

• Nylon is a synthetic material made through scientific research. It is strong, durable, and comfortable.
• Science also helps find environment-friendly ways to make clothes — such as natural dyes and fabrics that can be recycled.

Science in Industry

Science helps industries make things faster, safer, and cheaper:

• Machines developed through science do tasks quickly and with fewer mistakes.
• New materials made through science are stronger and lighter, improving products like cars and phones. The process of shaping and assembling these materials in a factory is called manufacturing.
• Science helps industries use less energy and reduce pollution, which is good for the environment.
• Recycling — companies use scientific technology to turn waste materials into useful products, reducing the need for new raw materials.

Every time a recycling company turns old bottles into new ones, it applies science to protect the environment.

Career Opportunities in Science

Science opens a wide range of career opportunities in healthcare, engineering, environmental science, agriculture, and technology. The demand for science professionals continues to grow.

Table 1.1 — Science-Related Careers

Which career connects most closely to what you enjoy in Integrated Science? That is where your pathway begins. The STEM departments at Senior School are the pathways that lead to these careers.

What Is STEM?

STEM stands for Science, Technology, Engineering, and Mathematics. Integrated Science gives you the basic knowledge and skills needed to specialise in one of the STEM fields at Senior School.

STEM education is important because it helps people invent new technologies that improve lives — for example, smartphones and clean energy. Many jobs require STEM knowledge, giving learners more career choices. Choosing a STEM pathway means choosing to help design Kenya's future hospitals, bridges, farms, and technologies.

Table 1.2 — STEM Pathway at Senior School

Project: Constructing a Career Chart

A career chart is a visual display that organises careers into categories so you can see the full range of opportunities at a glance. It can take the shape of a grid, a pie chart, or a tree diagram.

Steps to Build Your Career Chart

1. Decide on the structure — grid, pie chart, or tree diagram.
2. Use a ruler and pencil to lightly sketch the layout on a large cardboard or manila paper.
3. List the careers you want to include.
4. Divide the chart into sections labelled by category (e.g. Chemistry Careers, Biology Careers, Physics Careers) and label each section clearly with a marker.
5. Write each career name in the correct section.
6. Draw a simple icon or symbol for each career — for example, a syringe for a doctor.
7. Ensure all writing is legible and neat.
8. Hang the chart on the school notice board to inspire others.

Key Points — Introduction to Integrated Science

• Integrate means to combine one thing with another to form a whole.
• Integrated Science is a learning area that combines various branches of science.
• The three components are Physics (matter and energy), Chemistry (composition and changes of matter), and Biology (living things).
• Science improves agriculture through better tools (tractors, irrigation pumps, pesticide sprayers), improved seeds, and pest control.
• Science improves health through vaccines, medicines, and instruments — stethoscope, thermometer, syringe, and X-ray machine.
• Science improves food through processing, packaging, and preservation that keeps food safe and fresh.
• Science creates synthetic materials like nylon for textiles — strong, durable, and environment-friendly.
• Science improves transport through electric vehicles that produce no exhaust fumes.
• Science improves industry through better machines, new materials, and recycling technology.
• Science offers careers across healthcare, engineering, environmental science, agriculture, and technology.
• STEM stands for Science, Technology, Engineering, and Mathematics.
• The four STEM departments at Senior School are Pure Sciences, Applied Sciences, Technical and Engineering, and Career and Technology Studies.

Laboratory Safety — Sub-Strand Introduction

Laboratory safety is important for ensuring the well-being of everyone working in or near a laboratory. It involves understanding and following safety measures to prevent accidents and exposure to harmful materials. In this sub-strand you will learn about hazard symbols, causes of common accidents, first aid measures, and why safety rules matter.

What Is a Laboratory?

A laboratory is a place where learners conduct experiments to investigate scientific ideas. It contains essential apparatus, equipment, and instruments for carrying out experiments.

Where Can Laboratories Be Found?

• Schools — help learners experiment, observe, and discover science concepts.
• Universities — used for advanced research and teaching.
• Hospitals — used to test samples and diagnose diseases.
• Research centres — used to develop new knowledge and technologies.
• Some industries — used to test and improve products.

In schools, laboratories allow learners to engage in experimental learning — making it easier to understand science by doing, not just reading.

What Is a Hazard?

A hazard is a potential source of harm. A hazardous thing poses a potential risk to one's health, safety, or the environment. Hazardous substances can cause harm through exposure, release, or improper handling.

In the laboratory, different substances carry different hazards. Each hazard has a symbol — a small picture on the label of a container — that tells you what kind of danger the substance poses and how to handle it safely.

Table 1.3 — Common Hazard Symbols and Their Meanings

Flammable Substances

A flammable substance is one that can catch fire easily when placed near heat, sparks, or open flames. Flammable substances are identified in the laboratory by the flame hazard symbol — a simple flame shape inside a red-bordered diamond.

Safety Rules for Flammable Substances

• Always store flammable substances safely — away from heat sources, open flames, and sparks.
• Keep containers tightly closed when not in use.
• Use flammable substances only in a well-ventilated area.
• Never pour flammable liquids near an open flame.
• Handle with special protective equipment as indicated on the label.

Toxic Substances

A toxic substance is one that is harmful if inhaled, swallowed, or touched. It can cause illness or poisoning. Toxic substances are identified by the skull-and-crossbones symbol inside a red-bordered diamond.

Safety Rules for Toxic Substances

• Avoid all contact — do not inhale, swallow, or allow skin contact.
• Always wear gloves, safety goggles, and a laboratory coat when handling toxic substances.
• Work in a well-ventilated area or under a fume cupboard.
• Wash hands thoroughly with soap and running water after handling toxic substances.
• Never eat, drink, or touch your face while working with toxic substances.
• Handle with special protective equipment as indicated on the label.

Corrosive Substances

A corrosive substance is one that can cause a burning effect on the skin and eyes, or damage materials and surfaces it contacts. Corrosive substances are identified by the corrosive symbol — a picture of liquid dripping onto a surface and a hand inside a red-bordered diamond.

Safety Rules for Corrosive Substances

• Avoid all contact with skin, eyes, and clothing.
• Always wear gloves, safety goggles, and a laboratory coat.
• If corrosive liquid spills on your skin, rinse immediately with large amounts of cold running water for at least 15 minutes.
• If corrosive liquid splashes in your eyes, flush with running water for at least 15 minutes and seek medical help.
• Store corrosive substances in designated, clearly labelled areas.

Radioactive Substances

A radioactive substance is one that emits energy in the form of radiation. Radiation can cause harm to body organs. Radioactive substances are identified by the trefoil symbol — three fan-blade shapes arranged in a circle — usually on a yellow background with a black border.

Safety Rules for Radioactive Substances

• Handle with special protective equipment designed for radiation.
• Minimise time near the substance and keep a safe distance where possible.
• Never handle radioactive substances without the guidance of a trained adult.

Carcinogenic Substances

A carcinogenic substance is one that can promote (cause or increase the risk of) cancer. Carcinogenic substances are identified by a symbol showing a person with a starburst pattern, inside a red-bordered diamond.

Safety Rules for Carcinogenic Substances

• Avoid all exposure to carcinogenic substances.
• Always ensure proper ventilation when working in an area where carcinogenic substances are present.
• Wear appropriate personal protective equipment (PPE).

Comparing Radioactive and Carcinogenic Hazards

Causes of Common Laboratory Accidents

Laboratory accidents often occur due to improper safety measures. The most common accidents are cuts, burns and scalds, and ingestion of harmful substances. Other accidents include breakage of glassware, falling or slipping, inhaling fumes, and electric shocks.

Causes of Burns and Scalds

• Burns are caused by dry heat — such as open flames or hot surfaces.
• Scalds are caused by heat from substances like hot liquids or steam.
• Handling hot equipment without protective clothing can cause burns and scalds.
• Exposure to open flames — for example, a laboratory coat sleeve catching fire — causes burns.
• Accidental spills of boiling water or hot chemicals cause scalds.

Causes of Cuts

• Cuts occur from sharp objects such as broken glassware, blades, or other sharp tools when they are mishandled or broken.
• Attempting to pick up broken glass without protective gloves is a common cause of cuts.

Causes of Ingestion of Harmful Substances

• Eating food near chemicals — food can become contaminated with harmful substances on the bench.
• Failing to wash hands with soap and running water after handling toxic substances, then eating or touching the face, allows chemicals to enter the body.

Other Causes

• Falling or slipping due to items left on the floor.
• Inhaling fumes, vapours, or smoke from chemicals.
• Electric shocks from faulty or wet electrical equipment.

To prevent laboratory accidents, proper supervision, safety training, and enforcement of rules are essential.

Burns and Scalds

A burn is an injury caused by dry heat — such as an open flame, a hot surface, or a hot metal object. A scald is an injury caused by wet heat — such as hot liquids, boiling water, or steam.

First Aid for Burns and Scalds

1. Immediately get the person away from the heat source to stop the burning.
2. Place the burned area under cold running water for about ten to fifteen minutes.
3. Do not apply ice, iced water, oil, butter, flour, creams, or powders — these make the damage worse.
4. Do not puncture (burst) any blisters.
5. After cooling, cover the burn with a loose, light, non-sticky dressing such as plastic wrap or a clear plastic bag.
6. Seek medical treatment if the burn is severe.

Cuts in the Laboratory

Cuts are common laboratory accidents caused by sharp objects such as broken glassware, blades, or other sharp tools when they are mishandled or broken.

First Aid for Cuts — Step by Step

1. Wash your hands to avoid introducing infection into the wound.
2. Apply gentle pressure with a clean bandage or cloth and elevate (raise) the cut above the level of the heart until bleeding stops.
3. Clean the cut — wash around the cut with soap and water, but do not get soap inside the cut.
4. Remove any foreign particles or dirt from the cut using clean tweezers.
5. Cover the cut with a bandage and secure it with tape or a pin.
6. Seek medical attention if the cut is too deep.

Ingestion of Harmful Substances

Ingestion means swallowing. In the laboratory, harmful substances can enter the body by being swallowed accidentally — usually because a learner ate or drank near chemicals, or did not wash their hands after handling toxic substances.

First Aid for Ingestion of Harmful Substances

1. Remove anything remaining in the person's mouth by covering your finger with a fabric and cleaning the mouth. If the suspected substance is a household cleaner or chemical, read the container label and follow the instructions for accidental poisoning.
2. Do not make the person vomit unless told to do so by a healthcare professional.
3. If the person does vomit, turn their head to the side to prevent choking.
4. Do not give the person anything to drink unless told to do so by a doctor.
5. Seek immediate medical help.

Other Accidents — Eye Splash and Fume Inhalation

• If a chemical splashes in the eyes: flush with plenty of running water for at least 15 minutes, then seek medical treatment.
• If a learner inhales chemical vapours, fumes, or smoke: move the person to an area with fresh air immediately.

The First Aid Kit

A first aid kit is a container holding items used to give immediate treatment for minor injuries before medical help is available. Every laboratory should have a clearly labelled and easily accessible first aid kit.

Common Items in a Laboratory First Aid Kit

Always wear appropriate Personal Protective Equipment (PPE) — gloves, safety goggles, and a laboratory coat — to minimise the risk of accidents.

Know the location of the nearest emergency exit, first aid kit, and water tap in your laboratory before starting any experiment. Report all accidents to the teacher or laboratory technician immediately, even if they seem minor.

First Aid for Cuts — Full Procedure

This block consolidates the full step-by-step first aid procedure for cuts and connects it to the first aid kit items used at each step.

Step-by-Step with Equipment

First Aid for Ingestion — Full Procedure

This block consolidates the full procedure for accidental ingestion of harmful substances and connects it to related emergency situations.

Full Ingestion Procedure

1. Remove anything remaining in the person's mouth using a fabric-covered finger.
2. Read the chemical container's label and follow its instructions for accidental poisoning.
3. Do not make the person vomit unless instructed by a healthcare professional.
4. If vomiting occurs, turn the person's head to the side to prevent choking.
5. Do not give anything to drink unless told to do so by a doctor.
6. Seek immediate medical help.

Why Vomiting Must Not Be Forced

Some chemicals cause more damage on the way back up than they did going down — for example, corrosive substances will burn the throat and mouth a second time if vomited. This is why a healthcare professional must advise on whether vomiting is safe.

Summary of All Three First Aid Procedures