AS Level Chemistry: Orbital Hybridization

AS Level Chemistry: Orbital Hybridization

Hybridization   13:16

AS LEVEL CHEMISTRY / REVISION NOTE

Orbital Hybridization

A high-yield guide to how atomic orbitals combine, why molecular shapes form, and how to identify sp, sp², and sp³ hybridization with confidence.

Atomic orbitals Sigma bonding Molecular geometry

Focus: electron domains → hybrid orbitals → shape

MOLECULAR MODE: ACTIVE

01 / CORE IDEA

What is hybridization?

Hybridization is the mixing of atomic orbitals on the same atom to form a new set of equivalent hybrid orbitals. These orbitals point in specific directions, allowing atoms to form strong sigma bonds and predictable shapes.

Exam tip: count regions of electron density around the central atom. Each single, double, or triple bond counts as one region.

02 / PROCESS

The orbital-mixing model

An s orbital can combine with one, two, or three p orbitals. The number of orbitals mixed determines the hybridization type and the geometry around the atom.

s p + hybrid

03 / REFERENCE TABLE

The three essential hybridization patterns

TYPE 01

sp hybridization

1 s orbital + 1 p orbital → 2 sp orbitals

Electron-pair geometry: linear

Bond angle: 180°

Example: carbon in ethyne, C₂H₂.

TYPE 02

sp² hybridization

1 s orbital + 2 p orbitals → 3 sp² orbitals

Electron-pair geometry: trigonal planar

Bond angle: 120°

Example: each carbon in ethene, C₂H₄.

TYPE 03

sp³ hybridization

1 s orbital + 3 p orbitals → 4 sp³ orbitals

Electron-pair geometry: tetrahedral

Bond angle: 109.5°

Example: carbon in methane, CH₄.

04 / WORKED EXAMPLES

Read the structure, identify the hybridization

BeCl₂ Two bonding regions around Be sp; linear; 180°

BF₃ Three bonding regions around B sp²; trigonal planar; 120°

CH₄ Four bonding regions around C sp³; tetrahedral; 109.5°

05 / SELF-CHECK

Revision checkpoint

A carbon atom in carbon dioxide forms two double bonds. What hybridization does the carbon atom use, and what is its molecular shape?

Answer: sp hybridization

The central carbon has two regions of electron density because each C=O double bond counts as one region. Two regions give sp hybridization and a linear shape with a 180° bond angle.

Revision rule: count electron regions first — hybridization becomes much easier.

IGCSE CHEMISTRY: METAL EXTRACTION REVISION

IGCSE CHEMISTRY: METAL EXTRACTION REVISION

metal extraction   13:03

METALS MASTERY IGCSE REVISION

Paper 4 Exam Breakdown

Analyze the mark distribution and core concepts of the Paper 4 Metals Mock Exam.

Marks per Topic (Total: 40)

Key Themes in this Paper:

• Redox Chemistry: Identifying reducing agents and oxidation steps.
• Industrial Economics: Why we use specific substances like cryolite and limestone.
• Structure & Properties: Linking atomic arrangement to physical strength.
• Reactivity Series: Predicting reactions based on metallic order.

The Extraction of Iron

In the Blast Furnace, iron is reduced from haematite. Explore the chemical hierarchy from raw material to molten metal.

Exam Focus: Carbon Monoxide

Candidates often miss the formation equation: CO₂ + C → 2CO. This is the main reducing agent.

Chemical Zone Explorer

Blast Furnace Zone Simulator

Click a zone in the furnace to see the reaction.

Aluminium: The Electrolysis Cell

Aluminium extraction requires electricity. This section visualizes the ionic flow and electrode reactions.

Hall-Héroult Cell Logic

Why Cryolite? Aluminium Oxide melts at 2000°C. Cryolite lowers this to ~950°C, saving massive energy costs.

Select an electrode to see the redox equation

The Carbon Consumption Issue

The oxygen produced at the anode reacts with the graphite itself.

C(s) + O₂(g) → CO₂(g)

*This is why anodes must be replaced regularly, an essential point for IGCSE Question 2(d).

Zinc & Reactivity

Understand the transition from Zinc Blende to pure Zinc and its role in protecting Iron (Galvanising).

The Reactivity Spectrum

Adjust the slider to see which metals are extracted by carbon vs electrolysis.

Middle Reactivity

Extracted using Carbon in a furnace.

Sacrificial Protection

Zinc is more reactive than Iron. It 'sacrifices' itself by losing electrons more easily.

Fe → No reaction
Zn → Zn²⁺ + 2e^-

Alloys: Structure vs Property

Pure metals are often too soft for industrial use. Here we see how atomic disruption creates strength.

Particle Arrangement Visualizer

Try to "slide" the layers mentally. In the alloy, the different sized atoms act as "roadblocks".

The Sliding Theory

In pure iron, atoms are arranged in regular layers. These layers slide over each other easily when hit.

The Disruption Theory

In steel, carbon atoms (of different sizes) disrupt the regular arrangement. This locks the layers in place.

IGCSE Chemistry Revision Platform • Focused on Paper 4: Metals

© 2024 Interactive Learning Labs. All chemical equations verified against 0620 Syllabus.

Data Booklet - AS/A Level Chemistry

Data Booklet - AS/A Level Chemistry

Chemistry   16:05

 Click here to download the data booklet

IGCSE CHEMISTRY-EXTRACTION OF METALS

IGCSE CHEMISTRY-EXTRACTION OF METALS

metal extraction   12:32

 IGCSE CHEMISTRY-EXTRACTION OF  METALS

 

 

Atomic Structure and Electrons in Atoms - AS Level Chemistry

Atomic Structure and Electrons in Atoms - AS Level Chemistry

nuclear atom   08:29

 Atomic Structure and Electrons in Atoms - AS Level Chemistry Presentation

 

 

Answer Key_Simulation Test

Answer Key_Simulation Test

igcse exam   14:04

 

To download the question paper: here

Chemical Energetics-Simulation Test

Chemical Energetics-Simulation Test

igcse exam   14:00

 

 

The answer key is here

(HANDOUT) IGCSE Chemistry-Redox Reactions

(HANDOUT) IGCSE Chemistry-Redox Reactions

reduction   13:53

REDOX REACTIONS

• Redox stands for reduction oxidation.
• Redox reaction, also called oxidation reduction reaction, is a chemical reaction in which one substance is reduced and another is oxidised simultaneously.
• Oxidation and reduction of substances occur simultaneously. As one substance is reduced the other is oxidised.
• An oxidising agent is a substance that causes the oxidation of the other substance. Therefore, the substance that is reduced in a reaction is the oxidising agent.
• A reducing agent is a substance that causes the reduction of the other substance. For example, the substance that is oxidised in a reaction is the reducing agent.

OXYGEN IN REDOX REACTION

• Oxidation is the gain of oxygen by the substance. A substance that has gained oxygen is said to be oxidised.
• Reduction is the loss of oxygen by the substance. A substance that has lost oxygen is said to be reduced.

HYDROGEN IN REDOX REACTION

• Oxidation is the loss of hydrogen by the substance. A substance that has lost hydrogen is said to be oxidised.
• Reduction is the gain of hydrogen by the substance. A substance that has gained hydrogen is said to be reduced.

ELECTRONS IN REDOX

• Oxidation is the loss of electrons. A substance that loses electrons is oxidised.
• Reduction is the gain of electrons. A substance that gains electrons is reduced.
• The reaction below shows a redox reaction involving the gain and loss of electrons. 

OXIDATION NUMBER

• Oxidation number, also called oxidation state, is the number of electrons an atom gains or losses in a chemical combination.