Lewis_Structure_Presentation with pic and vid

all about Lewis structure

1. Introduction to Lewis Structures Understanding Chemical Structures Your Name or Institution Date of Presentation

2. Introduction to Chemical Bonding Definition: What is chemical bonding? Types of Bonds: - Ionic bonds - Covalent bonds - Metallic bonds Importance: Why is it essential to understand bonding and molecular structure?

3. What is a Lewis Structure? Definition: A representation of molecules showing how valence electrons are arranged among atoms. Purpose: Helps visualize the arrangement of electrons and bonds in a molecule. Named After: Gilbert N. Lewis.

4. Key Concepts of Lewis Structures Valence Electrons: Electrons in the outermost shell that participate in bonding. Electron Pairs: - Bonding pairs - Lone pairs Octet Rule: Atoms tend to bond in a way that they have 8 electrons in their valence shell.

5. How to Draw a Lewis Structure? (Step-by-Step) 1. Count Valence Electrons 2. Determine the Central Atom 3. Draw Single Bonds Between Atoms 4. Distribute Remaining Electrons 5. Form Double or Triple Bonds if Necessary

6. Example 1: Lewis Structure of Water (H₂O) Steps for H₂O: 1. Count total valence electrons (2 H + 1 O = 8 electrons). 2. Draw O in the center and bond two H atoms with single bonds. 3. Distribute lone pairs on the O atom.

7. Example 2: Lewis Structure of Carbon Dioxide (CO₂) Steps for CO₂: 1. Total valence electrons = 16 (4 from C + 6 from each O). 2. Carbon in the center, with two oxygen atoms on the sides. 3. Form two double bonds to satisfy the octet rule.

8. Exceptions to the Octet Rule Less than an Octet: Elements like Hydrogen (H) and Boron (B). More than an Octet: Elements like Phosphorus (P) and Sulfur (S) can have expanded octets. Odd Number of Electrons: Free radicals like Nitric Oxide (NO).

9. Resonance Structures Definition: Some molecules can have multiple valid Lewis structures (e.g., O₃). Example: Draw possible resonance forms and explain electron delocalization.

10. Importance of Lewis Structures in Chemistry Predict Molecular Geometry: Helps in predicting the shape of molecules using VSEPR theory. Understanding Polarity: Helps to understand the distribution of charge in a molecule. Foundation for More Complex Theories: Such as Molecular Orbital Theory.

11. Summary Key Takeaways: - Lewis structures help visualize bonding in molecules. - Follow the octet rule, but be aware of exceptions. - Understand the concept of resonance and its significance.

12. Questions? Invite Questions from the Audience