Lewis Structure Generator

Generate molecular structural layouts and count formal valence octets.

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Calculation Parameters

Specify your chemical inputs.

Calculated Result

Lewis Layout Representation

H - O - H
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Expert Tip

Double check molecular weights and balance equations to ensure stoichiometric ratios are correct.

How this Calculator Works

This generator visualizes Lewis dot structures and bonding setups for selected covalent molecules. Select the molecule from the dropdown below:

  • Molecule: Choose the chemical species (Default: CO2)

The results are computed instantly and updated in the results panel on the right.

Formula & Methodology

Total Valence Electrons = ฮฃ (Valence Electrons of atoms) - Net Charge

Where:

  • Valence Electrons: Total bonding and non-bonding outer-shell electrons in the structure.
  • Octet Rule: Atoms share electrons to achieve a stable configuration of 8 electrons (or 2 for Hydrogen).

Step-by-Step Calculation Example

To draw the Lewis structure of Carbon Dioxide ($CO_2$) manually, follow these steps:

  1. Identify the input parameters. For example:
    • Formula = CO2
    • Carbon valence electrons = 4
    • Oxygen valence electrons = 6 (Quantity: 2)
  2. Apply the formula:
    1. Total electrons: 4 + 2 * 6 = 16 2. Form single bonds: O - C - O (uses 4 e-, 12 remaining) 3. Add lone pairs to oxygens: :O - C - O: (uses 12 e-, 0 remaining) 4. Form double bonds to satisfy carbon octet: O = C = O
  3. Verify the calculated value which is updated instantly in the results panel on the right.

Frequently Asked Questions

What is a Lewis structure? โ–ผ

A Lewis structure is a 2D diagram representing valence electron distribution, covalent bonds, and lone pairs in a molecule.

What is the Octet Rule? โ–ผ

Main group elements tend to bond so that each atom has 8 valence electrons in its outer shell.

Which elements are exceptions to the octet rule? โ–ผ

Hydrogen (duet = 2), Beryllium (4), Boron (6), and expanded octet elements in Period 3 and below (e.g. SF6, PCl5).

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