What is VSEPR theory?

VSEPR (Valence Shell Electron Pair Repulsion) theory predicts molecular geometry based on electron pair repulsion. Common shapes include tetrahedral (109.5°), trigonal planar (120°), linear (180°), bent (~104.5°), and octahedral (90°). Use AZRS ChemMaker's VSEPR tab to visualize each geometry interactively.

How do I draw Lewis structures online?

AZRS ChemMaker's 2D drawing canvas lets you place atoms and draw single, double, triple, wedge, and dash bonds. Select an atom from the element grid, click on the canvas to place it, then drag to draw bonds — exactly like drawing Lewis structures on paper.

What is molecular geometry for water (H₂O)?

Water has a bent molecular geometry with a bond angle of approximately 104.5°. It has 2 bonding pairs and 2 lone pairs on the central oxygen atom. Search 'water' in AZRS ChemMaker to see its 3D model and VSEPR shape instantly.

How do I calculate molecular weight online?

Search any compound by name, formula, or SMILES in AZRS ChemMaker and the molecular weight (molar mass) appears instantly in the Info panel. Supports 900+ compounds from the PubChem database.

What is the difference between wedge and dash bonds?

In 3D structural drawings: a solid wedge bond points toward the viewer (coming out of the page), while a dashed/hashed bond points away from the viewer (going into the page). AZRS ChemMaker draws both automatically when you load a 3D structure.

Can I view molecules in 3D for AP Chemistry?

Yes! AZRS ChemMaker provides ball-and-stick, space-filling, wireframe, and stick-only 3D rendering. Switch to '3D View' or '2D+3D' split view. Drag to rotate, scroll to zoom. Perfect for AP Chemistry, IB Chemistry, and college organic chemistry.

What molecular geometries does the VSEPR viewer support?

AZRS ChemMaker supports all major VSEPR geometries: linear, bent, trigonal planar, tetrahedral, trigonal pyramidal, trigonal bipyramidal, octahedral, square planar, seesaw, and T-shaped — all with interactive 3D rotation and lone pair visualization.

Free Molecular Structure Builder 2026 – Draw & Visualize Molecules in 3D

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flat formula + 3D perspective drawing

2D · flat

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Draw or search a molecule

Pick a bond tool · or search by name above

3D · perspective

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Search a molecule

to see teacher-style 3D drawing

View:

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0 atoms

✏️ 2D Structure flat skeletal formula

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🔮 3D Model drag to rotate · scroll to zoom

Building 3D model…

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— atoms

Building 3D model…

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Auto-detect from formula:

Tetrahedral

Example: CH₄, CCl₄

Bond angle: 109.5°

Ready — search or draw a molecule to begin

CID: —

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Search a molecule to begin

Or draw one in the canvas

COMMON MOLECULES

RECENT SEARCHES

LIPINSKI'S RULE OF 5

Drug-like molecules typically have:
• MW ≤ 500 g/mol
• XLogP ≤ 5 (lipophilicity)
• H-donors ≤ 5
• H-acceptors ≤ 10

BOND TYPES

Single — σ bond, free rotation
Double ═ σ + π, rigid
Triple ≡ σ + 2π, linear
Wedge ▶ coming out of plane
Dash ··· going into plane

3D RENDER STYLE

3D SETTINGS

Atom size8

Bond size3

Rotate spd3

3D BACKGROUND

DRAW ELEMENT

SAVED MOLECULES

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