How to Use These Notes

This section provides guidance on effectively utilizing the revision notes:

• Notes are organized according to the AQA Year 1 & AS syllabus (from Sept 2015)
• Each chapter contains individual revision cards covering all necessary topics
• Italic text indicates optional knowledge for excelling students
• Bold text represents important keywords or key definitions
• 'Data sheet' indicates information provided during the exam

Memorization technique:

1. Read the title and keywords on a separate page
2. Attempt to write down the card's content without looking at the next page
3. Use keywords as hints about the content
4. Write everything you remember, even if unsure
5. Check and rewrite incorrect answers

For unfamiliar cards:

• Read them a few times first
• Use a covering technique to gradually reveal content while trying to recall covered information

Highlight: This active recall technique is designed to enhance memorization and retention of key chemistry concepts.

Example: When reviewing a card on atomic structure, cover the content and try to recall definitions and key points based on the title and keywords before revealing the full information.

Amount of Substance

This section focuses on the concept of the mole and related calculations, which are essential for AQA A Level Chemistry students.

Mole & Molar Gas Volume:

• One mole is the amount of substance containing 6.02 x 10²³ particles (Avogadro's constant)
• The molar gas volume is the volume occupied by one mole of any gas at room temperature and pressure (24 dm³ at RTP)

Empirical and Molecular Formulae:

• Empirical formula: The simplest whole number ratio of atoms of each element in a compound
• Molecular formula: The actual number of atoms of each element in a molecule

Water of Crystallisation & Types of Crystal Structures:

• Some ionic compounds contain water molecules in their crystal structure
• The formula for a hydrated salt includes the number of water molecules, e.g., CuSO₄·5H₂O

Definition: Water of crystallisation - Water molecules that are present in the crystal structure of a salt.

Example: Calculating the empirical formula of a compound from its percentage composition is a common exam question in AQA A Level Chemistry.

Periodicity

This section focuses on the periodic table and trends in element properties, which is a fundamental concept in AQA A Level Chemistry.

Periodic Table & Periodic Trends:

• Elements are arranged in order of increasing atomic number
• Groups: Vertical columns with similar chemical properties
• Periods: Horizontal rows with gradually changing properties

Trends across periods and down groups:

• Atomic radius
• Ionization energy
• Electronegativity
• Melting and boiling points

Definition: Periodicity - The repetition of chemical and physical properties of elements as their atomic numbers increase.

Example: Explaining trends in reactivity and physical properties across a period or down a group is a common exam question in AQA A Level Chemistry.