Covalent Bonding Basics

Covalent bonding happens when atoms share electrons to fill up their outer shells - think of it like two friends sharing a pizza so they both get what they need! This type of bonding only occurs between non-metals, such as hydrogen, oxygen, carbon, and nitrogen.

The key thing to remember is that atoms are sharing pairs of electrons, not giving them away completely. This sharing creates strong bonds between the atoms within each molecule, but the molecules themselves are only held together by much weaker forces.

Quick Tip: If you see two non-metals in a compound (like H₂O or CH₄), you're looking at covalent bonding!

Simple covalent compounds have low melting and boiling points because when you heat them up, you're breaking the weak forces between molecules, not the actual covalent bonds. They also don't conduct electricity since there are no free electrons floating about - all the electrons are busy being shared between specific atoms.

Dot and cross diagrams are brilliant for visualising how this sharing works. You draw overlapping circles to show where atoms meet, then use dots for one atom's electrons and crosses for another's. For example, in water (H₂O), you'll see the oxygen sharing electrons with two hydrogen atoms, while in methane (CH₄), carbon shares with four hydrogens.