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What is covalent bonding?

Forming a covalent bond

These shared are found in the outer shells of the . In general, each atom contributes one electron to the shared pair of electrons.

Each atom then has a complete outer shell of electrons.

The slideshow shows how a covalent bond forms between a hydrogen atom and a chlorine atom, making hydrogen chloride.

Image gallerySkip image gallerySlide 1 of 2, Structures of a hydrogen atom and a chlorine atom., 1. A hydrogen atom with one electron and a chlorine atom with 17 electrons

Learn more on covalent bonding in this podcast.

Sizes of atoms and simple molecules

A simple molecule contains only a few atoms, so the sizes of atoms and simple molecules have a similar range of sizes. They are very small, typically around 0.1 nm or 10-10 m across.

Individual atoms and molecules are too small to see even with the strongest light microscope. Some electron microscopes can produce images of atoms and simple molecules.

Structure of a water molecule
Figure caption,
A water molecule is about 0.3 nm across

An explanation of covalent bonding