SOH-CAH-TOA

This repository contains organized study materials, guides, and practice tests designed to support students preparing for IGCSE exit examinations. It serves as a central resource hub for reviewing key topics across various subjects.

Resources are structured by subject and topic, allowing quick access to specific knowledge areas needed for exam preparation. Use this guide to plan study sessions and test understanding before exams.

Guideline: Always review material from both a Study Guide and its corresponding Quiz/Mark Scheme pair to ensure comprehensive understanding and proficiency.

C12 - Experimental techniques and chemical analysis

Apparatus and measurements Choose apparatus that measures the quantity needed with suitable precision. Quantity Apparatus Use and limitation Time Stopwatch Measures elapsed time; reaction start and stop can be judged inconsistently. Temperature Thermometer Measures temperature; read at eye level and allow the reading to stabilise. Mass Balance Measures mass; zero it before use and avoid drafts or spills. Liquid volume Burette Delivers variable, accurately measured volumes, especially in titrations. Liquid volume Volumetric pipette Transfers one fixed, accurate volume. Liquid volume Measuring cylinder Measures a range of volumes quickly, but less precisely than a pipette or burette. Gas volume Gas syringe Collects and measures gas directly; check connections for leaks. A measuring cylinder is convenient for approximate volumes. Use a pipette and burette when accurate solution volumes matter. Read liquid levels at eye level, using the bottom of the meniscus for colourless liquids. ...

B17 - Inheritance

Inheritance is the transmission of genetic information from one generation to the next. Genetic information is carried by DNA in chromosomes.

B15 - Drugs

What is a drug? A drug is a substance that modifies chemical reactions in the body. Drugs can change how cells, tissues, organs, or organ systems work. Some drugs are used as medicines to prevent or treat disease; other drugs may be harmful or addictive. The effect of a drug depends on the chemical reaction or process that it changes. A drug may: reduce symptoms; destroy or inhibit a pathogen; or change the activity of body cells. This guide focuses on antibiotics and antibiotic resistance. ...

M19 - Symmetry

Symmetry 1. Key vocabulary Line of symmetry: A line that divides a shape into two matching mirror-image halves. Rotational symmetry: A shape matches its original position after a rotation of less than one complete turn. Order of rotational symmetry: The number of times a shape matches itself during one complete turn of $360^\circ$. Axis of rotational symmetry: A line about which a shape or solid can be rotated and remain unchanged. Plane of symmetry: A flat plane that divides a solid into matching mirror-image halves. A shape can have line symmetry, rotational symmetry, both, or neither. ...

C11 - Organic Chemistry

Organic chemistry studies compounds containing carbon. This guide combines Core and Supplement (Extended) requirements for syllabus topic 11.