Chemical Bonding Lab

See how atoms bond, one step at a time. Watch electrons transfer to make ionic compounds or share to make molecules, then check the Lewis structure and spin the 3D shape. Pick a compound and press Next.

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Choose a compound

Pick Ionic to combine a metal with a non-metal, or Covalent to explore molecules such as water, carbon dioxide and ammonia.

Step through it

The lesson plays automatically as soon as you choose. Press Pause, then use Next and Back, the numbered steps or the ← → keys to go at your own pace. Replay repeats a step.

Explore the shape

On the last step, drag to rotate: the 3D shape of a molecule (covalent) or the crystal lattice (ionic). Turn lone pairs on or off to see why a molecule has its shape.

Ionic bonding in short

An ionic bond forms between a metal and a non-metal. The metal atom loses its outer electrons and becomes a positive ion (cation); the non-metal atom gains them and becomes a negative ion (anion). Both ions end up with a full outer shell, like a noble gas, and the opposite charges attract each other strongly. To write the formula, swap the charges: Al³⁺ and O²⁻ give Al₂O₃.

Covalent bonding and Lewis structures

Two non-metal atoms share pairs of electrons so that each reaches a full outer shell (8 electrons, or 2 for hydrogen). A shared pair is one bond: a single bond shares one pair, a double bond two and a triple bond three. Electrons that are not shared stay on their atom as lone pairs. In a Lewis structure each shared pair is drawn as a line and each lone pair as two dots. In a coordinate (dative) bond, as in NH₄⁺, both electrons come from the same atom.

Shapes of molecules (VSEPR theory)

Electron pairs around the central atom repel each other and spread out as far as possible. Lone pairs repel more strongly than bond pairs, so they squeeze the bond angles.

Bond pairs	Lone pairs	Shape	Bond angle	Example
2	0	Linear	180°	CO₂, BeCl₂, HCN
3	0	Trigonal planar	120°	BF₃, C₂H₄ (at each C)
4	0	Tetrahedral	109.5°	CH₄, CCl₄, NH₄⁺
3	1	Trigonal pyramidal	≈ 107°	NH₃, H₃O⁺
2	2	Bent (V-shaped)	104.5° (H₂O)	H₂O, H₂S

Practise what you learned

Test yourself with chapter-wise MCQs and explanations:

Theories of Covalent Bonding and Shapes of Molecules — Chemistry, HSSC-KPK First Year (699 questions)
Chemical Bonding — Chemistry, HSSC-Punjab First Year (915 questions)
Chemical Bonding — Chemistry, SSC-Punjab Class 9 (665 questions)

Works offline: after your first visit the lab is saved in your browser, so you can use it without an internet connection. Electron-shell diagrams use the simple 2, 8, 8, 2 arrangement taught in school courses.