Dot Diagram Designer
Draw Lewis structures for covalent molecules
What this lesson covers
Why it matters
Imagine two shy dancers who refuse to let go of each other's hands, sharing the space between them to stay balanced.
Predict first
Why do non-metal atoms share electrons instead of transferring them?
Non-metals have high electronegativity; sharing allows both to fill their outer shells without forming ions.
- To achieve a stable octet (or duplet) configuration — correct
- Because they are too heavy to move electrons
- To become positively charged ions
- Because electrons are sticky
What you do
Build methane (CH₄): carbon needs 4 more electrons and each hydrogen needs 1. Share one pair between carbon and each hydrogen until every outer shell is full — the finished Lewis dot structure.
Check yourself
In the dot structure of water (H₂O), how many lone pairs are on the Oxygen atom?
Oxygen has 6 valence electrons. It shares 2 with Hydrogens, leaving 4 electrons (2 pairs) as lone pairs.
What does a single line in a structural formula represent in a dot diagram?
A single covalent bond is formed by the sharing of one pair of electrons between two atoms.
Why does Nitrogen form a triple bond in N₂?
Nitrogen has 5 valence electrons. It needs 3 more to reach 8, so it shares 3 pairs with another Nitrogen atom.
- 0 lone pairs
- 1 lone pair
- 2 lone pairs — correct
- 3 lone pairs
- One shared pair of electrons — correct
- One lone pair of electrons
- Two shared pairs of electrons
- An ionic attraction
- To share 3 pairs and complete its octet — correct
- Because Nitrogen has 3 protons
- To form 3 ions
- Because it is a metal