Unit Summaries Flashcards

Flashcards covering key terms and concepts from the unit summaries.

Metals

Good electrical and heat conductors, high densities and melting points, high lustre, high tensile strength, malleable and sonorous.

Non-metals

Do not conduct electricity, are poor thermal conductors, have very high melting points, and are strong.

Plastics

Man-made materials made of organic molecules called polymers, waterproof, hard-wearing, heat and electrical insulators.

Reactivity Series

A list of metals arranged in order of their reactivity.

Oxides

Compounds formed when metals react with oxygen.

Sacrificial protection

A method to protect steel by bolting zinc blocks to it, allowing zinc to corrode instead.

Corrosion

The process by which metals are damaged due to the formation of ores or oxides.

Iron Rusting

The process where iron reacts with water and air to form hydrated iron oxide.

Neutralisation Reaction

A chemical reaction in which an acid and a base react to form salts and water.

Acids

Chemicals that release hydrogen ions in water, have a sour taste, and turn blue litmus paper red.

Strong Acids

Acids that completely dissociate in water, examples include hydrochloric acid and sulfuric acid.

Weak Acids

Acids that partially dissociate in water, examples include citric acid and ascorbic acid.

Alkali

A base that dissolves in water.

pH Scale

A scale used to measure how acidic or alkaline a solution is.

Indicators

Chemicals that change color to show the presence of an acid or alkali.

Universal Indicator

A pH indicator that shows the acidity or alkalinity of a solution through color changes.

Solute

The solid part of a solution that dissolves in a liquid.

Solvent

The liquid in which a solute is dissolved.

Suspension

A mixture where fine particles of an insoluble substance are distributed throughout a liquid.

Colloid

A mixture where tiny particles of an insoluble substance do not settle out.

Emulsion

A colloid formed when one liquid is dispersed in another, such as milk.

Hard Water

Water that contains dissolved calcium and magnesium and does not lather easily with soap.

Scum

A precipitate formed when soap reacts with hard water.

Detergents

Chemical agents used to remove dirt and stains from surfaces.

Abrasives

Materials used to grind and polish softer materials.

Micro-organisms

Tiny organisms that can cause food decay and require oxygen, water, and suitable temperatures to grow.

Food Preservation

Methods to prevent or slow down the decay of food.

Preservatives

Substances added to food to prevent spoilage.

Sewage

Waste water generated in households.

Desalination

The process of removing dissolved salts from water.

Water Cycle

Natural cycle that replenishes fresh water through evaporation and precipitation.

Upthrust

The force in a liquid that pushes upward on an object.

Friction

A force that opposes the movement of an object through a fluid.

Projectile

An object that is thrown through the air, described by its trajectory.

Eutrophication

The enrichment of water by nutrients leading to excessive plant growth and depletion of oxygen.

Pollution

The contamination of the environment with harmful substances.

Scuba-diving Hazards

Risks associated with scuba diving include nitrogen narcosis and the bends.

Echo sounders

Devices used by fishermen to locate shoals of fish.

Limescale

Deposits formed in hard water due to calcium and magnesium.

Abrasive Action

The process of cleaning surfaces through grinding or polishing.

Bunsen Burners

A type of gas burner used in laboratories.

Artificial Radiation

Radiation that can cause damage to body cells.

Household Chemicals

Products used in homes for cleaning, hygiene, and food preparation.

First Aid

Emergency treatment administered to an injured person.

Safety Symbols

Internationally recognized signs indicating potential hazards.

Fire Triangle

Heat, oxygen, and fuel are necessary for a fire to burn.

Chemical Fires

Fires caused by combustible chemicals that can emit poisonous gases.

Fire Extinguisher

A device used to extinguish fires.

Waste Management

The efficient disposal of waste with minimal environmental impact.

Hard Water Removal

Methods such as boiling or adding washing soda to soften water.

Colloidal Suspension

A mixture in which particles are dispersed without settling.

Micelles

Droplets formed by detergent molecules that trap dirt.

Food Preservation Methods

Techniques like freezing, canning, and dehydrating to prevent food spoilage.

Chemical Reactions

Processes that modify the chemical structure of substances.

Antiseptic

A chemical used to kill micro-organisms on living tissue.

Disinfectant

A chemical that kills micro-organisms on inanimate surfaces.

Mains Electricity Safety

Procedures aimed at using electricity safely.

Electric Shock Treatment

Rescue measures to administer when someone has electrical injuries.

Sprains Treatment

Injury management techniques utilizing bandaging.

Burn Classification

Categorization of burns based on the extent of skin damage.

Chemical Waste

Hazardous by-products from chemical processes.

Nutrient Enrichment

The process by which soil or water assumes high nutrient levels, often leading to pollution.

Waste Recycling

Reprocessing of materials to reduce waste.

Bleaching Agents

Chemicals added to products to remove color and stains.

Frozen Food Storage

Preserving food by keeping it at low temperatures.

Bacterial Growth Conditions

Optimum levels of warmth, moisture, and nutrients for bacteria to flourish.