Science Book 1: Lower Secondary Curriculum Notes

Introduction to Science and Laboratory Procedures

Science is an exciting subject based on knowledge and conducting experiments to find answers to problems. It is divided into several major branches:

Biology: The study of living things.
Chemistry: The study of chemicals and how to change them.
Physics: The study of energy, matter, and movement.
Geology: The study of rocks and the Earth.
Astronomy: The study of planets, stars, and the universe.
Ecology: The study of how plants and animals interact within the environment.

General Safety Rules in the Laboratory

The laboratory contains gas taps, burners, glassware, and electrical points, necessitating strict safety rules:

Entry: Do not enter the science room without a teacher. Always wear a lab coat and proper flat, closed shoes.
Conduct: No running or pushing; the floor is hard and slippery.
Organization: Keep notebooks neat and away from experiment areas.
Prohibited Items: Never eat food, lollies, chew gum, or drink from laboratory glassware.
Hygiene: Do not taste or inhale chemicals. Wash hands after lab work, especially before eating.
Waste Disposal: Pour liquids into sinks/waste bottles. Place solids in bins. Broken glass requires special bins.
Maintenance: Clean all equipment and workbenches after use and return items to their proper place.

Rules for Heating and Mixing Chemicals

Vessel Orientation: Never look inside a flask or beaker while heating. Do not point the open end of a test tube at yourself or others.
Protective Gear: Wear safety goggles during heating.
Lighting: Follow the specific method for lighting a Bunsen burner.
Handling: Let equipment cool before picking it up to avoid burns.
Hair Safety: Keep long hair tied back and away from flames.
Flammables: Keep flammable substances away from naked flames.

Accident Procedures

Reporting: Report all breakages or damage to the teacher immediately.
Spills: If acid or chemicals touch skin, wash with a large volume of running tap water.
Fire: If clothing catches fire, smother it with a blanket or coat. Never run.

Hazardous Material Safety Labels

Poison: Represents toxic substances like Chloroform.
Flammable: Represents materials like Methylated spirit that ignite easily.
Corrosive: Represents substances like Caustic soda or concentrated Hydrochloric acid that destroy surfaces and skin.
Explosive/Explosion Hazard: Represents highly reactive materials like Sodium in water.

Working with Laboratory Equipment

The Microscope

A microscope magnifies objects too small for the naked eye.

Types of Microscopes:
- Simple Microscope: Uses one magnifying lens in a tube.
- Compound Microscope: Uses two lenses (eyepiece and objectives) and focuses light through an object.
- Stereo/Dissecting Microscope: Used for thicker objects and observing tissues during dissection.
Caring for the Microscope:
- Carry with two hands: one on the base and one on the arm.
- Store in a box or under a dustproof cover.
- Lenses must only be cleaned with special tissue paper.
Preparing a Wet Mount:
1. Place the specimen in the center of a clean, dry slide.
2. Add a drop of water (or liquid medium).
3. Add a stain if needed (Iodine for animal cells, Methylene blue for plant cells).
4. Lower the coverslip on top to keep the specimen flat and protect the objective lens.

The Bunsen Burner

Invented by Robert Bunsen in $1855$ .

Lighting Procedure:
1. Connect the rubber tube to the gas outlet.
2. Close the air hole by turning the collar.
3. Light a match and hold it over the barrel.
4. Turn on the gas last.
5. Safety Flame: When the hole is closed, the flame is bright yellow, sooty, and less hot.
6. Heating Flame: When the hole is open, air mixes with gas to produce a hotter, pale blue flame.
Test Tube Heating Rules:
- Fill no more than one third full.
- Use a test tube holder.
- Move the tube to and fro in the flame.
- Heat the side, not the bottom.

Measuring Instruments and Units

Fiji uses the metric system for measurements.

Volume: Measured in liters ( $L$ ) or milliliters ( $mL$ ) using beakers or measuring cylinders. Always read the bottom of the meniscus (the curve of the liquid).
Length: Measured in meters ( $m$ ). Tools include trundle wheels, metre rules, and tape measures.
Mass: The amount of matter in an object, measured in grams ( $g$ ) or kilograms ( $kg$ ) using beam balances or electronic scales.
Time: Measured in seconds ( $s$ ) using watches or stopwatches.
Temperature: Measured in degrees Celsius ( $ºC$ ) using a thermometer.

Scientific Investigation and Data

Observations and Inferences

Observation: Noticing things using the five senses (e.g., lemons taste sour).
Inference: A likely explanation for an observation (e.g., lemons are sour because they contain acid).
Hypothesis: A testable guess for a problem.
Control: A standard used for comparison in an experiment.

Scientific Method Steps

Observing: Noting details about a situation.
Inferring: Thinking of an explanation.
Hypothesis: Making a testable guess.
Design: Planning a fair experiment with a control.
Experiment: Performing the test and studying results.
Conclusion: Deciding if results prove or disprove the hypothesis.

Formatting Practical Reports

Title: Name of the experiment.
Introduction/Aim: Background and the purpose of the study.
Hypothesis: Educated guess of discovery.
Materials: List of equipment and chemicals.
Method: Detailed account of procedures and diagrams.
Results/Observations: Data presented in lists, tables, or graphs.
Discussion: Explanation of results and difficulties encountered.
Conclusion: Short statement relating directly to the aim.

Displaying Data

Tables: Organised grids used to study relationships between data sets.
Graphs:
- Bar Graphs: Used to display and compare data across groups.
- Line Graphs: Show how data changes over time; most common in science.
- Pie Charts: Represent portions of a whole ( $100\%$ ). To convert percentage ( $X$ ) to degrees ( $Y$ ): $3.6^\circ \times X\% = Y^\circ$ .

Matter and the Particle Theory

Atomic Models

Dalton ( $1807$ ): The atom is a hard, dense sphere.
Thomson ( $1903$ ): Electrons are scattered throughout the atom.
Rutherford ( $1911$ ): Atom has a dense nucleus of protons and neutrons, surrounded by orbiting electrons.

Atomic Structure

Protons: Positively charged particles in the nucleus.
Neutrons: Particles with no charge in the nucleus.
Electrons: Negatively charged particles in shells orbiting the nucleus.
Atomic Number (Z): The number of protons in an atom (determines the element).
Mass Number: The sum of protons and neutrons.

States of Matter

Solids: Particles are in a fixed pattern, held closely, and vibrate. They have fixed volume and shape.
Liquids: Particles have more energy and space, allowing them to flow. They have no definite shape and take the form of the container.
Gases: Particles move freely and loosely. They have no fixed volume or shape and fill any container.

Changes of State

Sublimation/Melting: Gas/solid turns to liquid (requires heat).
Boiling/Evaporation: Liquid turns to gas (requires heat).
Freezing: Liquid turns to solid (cools).
Condensation: Gas turns to liquid (cools).

Materials and Their Environment

Classification of Materials

Ceramics: Made from clay and sand (e.g., chinaware, bricks).
Plastics: Synthetic materials made from crude oil.
- PVC: Used for pipes and raincoats.
- Polystyrene: Used for packaging and cups.
- Polythene: Used for bags and food wrappers.
- Bakelite: Tough, heat-resistant plastic for plugs and cameras.
Alloys: Mixtures of metals (e.g., steel, brass, bronze).
Composite Materials: Combinations, like plastic reinforced with glass fiber.

Water Types

Hard Water: Contains high mineral salts (Calcium and Magnesium). It does not lather easily with soap, forms "scum," and creates "kettle fur" (solid layers) when boiled.
Soft Water: Contains few minerals. Lathers easily.
Detergents vs. Soaps: Detergents lather in hard water and are usually made from petroleum. Unlike soap, most detergents are not easily destroyed by bacteria unless labeled "Biodegradable."

Chemical Reactions

Elements, Ions, and Molecules

Element: A pure substance made of one type of atom (e.g., Iron $Fe$ , Oxygen $O$ , Carbon $C$ ).
Ion: Formed when an atom gains or loses electrons.
- Cation: Positively charged (lost electrons).
- Anion: Negatively charged (gained electrons).
Molecule: Two or more atoms chemically combined (e.g., $O_2$ , $H_2O$ , $NH_3$ ).
Compound: More than one type of atom joined together (e.g., Glucose $C_6H_{12}O_6$ ).

Acids and Bases

Acids: Sour taste, corrosive, contain $H^+$ ions, pH less than $7$ . Turn blue litmus red.
- Common Acids: Acetic ( $CH_3COOH$ ), Citric ( $C_6H_8O_7$ ), Hydrochloric ( $HCl$ ), Sulphuric ( $H_2SO_4$ ).
Bases: Bitter taste, soapy feel, contain $OH^-$ ions, pH greater than $7$ . Soluble bases are called alkalis.
- Common Alkalis: Sodium hydroxide ( $NaOH$ ), Calcium hydroxide ( $Ca(OH)_2$ ), Magnesium hydroxide ( $Mg(OH)_2$ ).
Neutralization: Acid + Base $\rightarrow$ Salt + Water.

Reaction Testing

Hydrogen Gas Test: Identified by a "pop" sound when a burning splint is introduced.
Carbon Dioxide Test: Identified by limewater turning "milky."

Equations

Word Equation: Iron + Oxygen $\rightarrow$ Iron oxide.
Chemical Equation: Balanced summary using symbols (e.g., $C + O_2 \rightarrow CO_2$ ).

Living Things and the Environment

Characteristics of Life (MRS GREN)

Movement: Changing position.
Respiration: Releasing energy from food.
Sensitivity: Responding to stimuli.
Growth: Increasing in size.
Reproduction: Producing offspring.
Excretion: Removing waste.
Nutrition: Obtaining food.

Ecosystems and Interactions

Ecosystem: A system linking energy, chemicals, producers, and consumers.
Symbiosis:
- Mutualism: Both species benefit.
- Commensalism: One benefits, the other is unaffected.
- Parasitism: One (parasite) benefits at the expense of the other (host).
Food Chains: Energy moves from Sun $\rightarrow$ Producers $\rightarrow$ Consumers $\rightarrow$ Decomposers.

Plant Responses (Tropisms)

Phototropism: Growth response to light (controlled by the hormone auxin).
Geotropism (Gravitropism): Response to gravity; roots grow down (positive).
Hydrotropism: Roots growing toward water.
Thigmotropism: Response to touch (e.g., tendrils coiling around support).

Conservation Groups in Fiji

WWF (World Wildlife Fund): Preserves wildlife and ecosystems.
BirdLife Fiji: Protects bird areas like the Natewa Tunuloa Peninsula.
NatureFiji – Mareqeti Viti: Focused on terrestrial conservation and indigenous heritage.

Plant Structure and Life Processes

Plant Anatomy

Roots: Provide anchorage and absorb water/minerals via root hairs.
Stem: Supports leaves/flowers and transports fluids through xylem (water) and phloem (food).
Leaves: The site of photosynthesis. Features include a waxy cuticle and stomata (pores controlled by guard cells).

Types of Plants

Algae: Simple water plants; include plankton.
Mosses: Small plants in moist areas; reproduce via spores in capsules.
Ferns: Have fronds and underground stems (rhizomes); reproduce via spores.
Conifers: Reproduce with seeds in cones (e.g., Dakua, Pine).
Angiosperms: Flowering plants; seeds are found inside fruit.

Photosynthesis

Equation: 6CO_2 + 6H_2_O + \text{light} \rightarrow C_6H_{12}O_6 + 6O_2

Factors: Light intensity, $CO_2$ concentration, temperature (ideal $25$ to $35ºC$ ), chlorophyll, and water.

Transpiration

The evaporation of water from leaves/stems. It keeps plants cool and draws up minerals.

Affecting Factors: Light, temperature, humidity, wind, and soil water.

Reproduction in Plants

Vegetative (Asexual): Growth from Runners, Stolons, Rhizomes, Bulbs, or Corms. Artificial methods include grafting, cuttings, and layering.
Sexual: Involves the flower. Male part is the stamen (anther/filament); female is the pistil (stigma/style/ovary).

Energy and Forces

Energy Sources

Renewable: Sun, wind, hydro, geothermal, biofuel, tides.
Non-renewable (Fossil Fuels): Coal, oil, natural gas.
Coal Formation Stages: Peat $\rightarrow$ Brown Coal (Lignite) $\rightarrow$ Black Coal (Bituminous) $\rightarrow$ Anthracite $\rightarrow$ Graphite.

Forms of Energy

Mechanical: Kinetic (movement) or Potential (stored).
Chemical: Stored in bonds (e.g., food, matches).
Thermal/Heat: Internal motion of atoms.
Electromagnetic: Travels in waves (e.g., light, microwaves).
Nuclear: Energy from the center of an atom (Fission or Fusion).

Reflection and Mirrors

Law of Reflection: Angle of incidence equals angle of reflection.
Plane Mirror: Image is virtual, upright, and same size.
Concave (Converging): Curved inward; used in dental mirrors and searchlights.
Convex (Diverging): Curved outward; used for security and car rear-view mirrors.

Forces

Friction: Force between surfaces that slows motion. Can be reduced by lubricants, streamlining, or ball bearings.
Magnetic: Push or pull without contact.
Gravity: Pulls objects toward the Earth's center. Weight is the force of gravity measured in Newtons ( $N$ ). Mass remains constant across different planets.

Earth and Beyond

Solar System Details

Terrestrial Planets: Mercury, Venus, Earth, Mars.
Gas Giants: Jupiter, Saturn, Uranus, Neptune.
The Sun: Contains $99.8\%$ of the solar system's mass. Core temperature is $14000000ºC$ .
Pluto: Reclassified as a "dwarf planet" in $2006$ .

Moon and Eclipses

Phases of the Moon: Caused by the relative positions of Earth, Moon, and Sun.
Tides: Caused by gravitational pull of the Moon and Sun. Spring tides (highest) occur when aligned; Neap tides (weakest) occur at right angles.
Solar Eclipse: Moon blocks the Sun from Earth's view.
Lunar Eclipse: Earth blocks the Sun from the Moon; the Moon appears reddish.

Seasons and Rotation

Day and Night: Caused by Earth's rotation every $24\,hours$ .
Seasons: Caused by the Earth's axis tilt of $23.5^\circ$ during its revolution around the Sun.

Climate Change

Global Warming: Increase in Earth's average surface temperature due to greenhouse gases ( $CO_2$ , Methane, CFCs, Nitrous oxides).
Greenhouse Effect: The natural warming of Earth's surface by its atmosphere. The enhanced greenhouse effect is the unnatural warming caused by human activity (burning fossil fuels, deforestation).