Covalent bond: sharing electrons, and Lewis dot structures sheet3-mark answer frameWhat is a covalent bond? Draw the Lewis dot structures of Cl₂ and N₂ and name the type of bond in each.
How to lay out the answer. Follow the frame, then write it in your own words.
- 1 · Define. A covalent bond forms when two atoms share a pair of electrons, each atom giving one.
- 2 · Chlorine. Each Cl (2, 8, 7) needs 1 electron. The two atoms share one pair: a single bond, Cl-Cl.
- 3 · Nitrogen. Each N (2, 5) needs 3 electrons. The two atoms share three pairs: a triple bond, N≡N.
- 4 · Draw both. Use dots for one atom and crosses for the other, with the shared pairs between the atoms. Check that each atom has 8 electrons.
- 5 · Close in one line. So the number of shared pairs decides whether a bond is single, double or triple.
Scoring tip: Count the electrons around each atom in your drawing. If an atom does not have 8 (hydrogen 2), the structure is wrong.
