Dot-and-Cross Diagrams and Lone Pairs · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Drawing every outer electron

Science · Matter & Materials · ages 14-15
Name ______________________   Date ____________

  1. Which pair counts as a lone pair?

    • A pair shared between two atoms
    • A pair sitting on one atom only
    • Any two dots anywhere

  2. In a dot-and-cross diagram, what do the dots and crosses show?

    • Which atom each outer electron came from
    • The speed of each electron
    • The size of the nucleus

  3. A chlorine atom sits in group 7. How many bonds does it usually form?

    • Two
    • Three
    • One

  4. A student counts only the shared pairs and skips the rest. What did they miss?

    • The lone pairs
    • The nuclei
    • The group numbers

  5. An atom in group 6 usually forms how many bonds?

    • One
    • Two
    • Four

  6. A diagram holds the right number of electrons but puts a lone pair on the wrong atom. Is it correct?

    • Yes, only totals matter
    • No, pairs must sit on the right atom
    • Yes, if the bonds look neat

  7. A diagram that omits lone pairs still shows every outer electron.

    Circle one:   True   False

  8. A nitrogen diagram shows five bonds. Using the group shortcut, what is wrong?

    • Group 5 nitrogen usually forms three, so recheck it
    • Nothing is wrong with five bonds
    • Add more lone pairs without thinking
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Drawing every outer electron W1-mt_ghK4a25usP-s1

  1. A pair sitting on one atom only · A lone pair sits on a single atom and bonds nothing.
  2. Which atom each outer electron came from · Dots mark one atom's electrons and crosses mark the other's.
  3. One · Group 7 atoms hold seven outer electrons and usually form one bond.
  4. The lone pairs · The unshared pairs are lone pairs, and they belong in the count.
  5. Two · Group 6 atoms like oxygen usually form two bonds.
  6. No, pairs must sit on the right atom · A right total with wrongly placed pairs is still wrong.
  7. False · Lone pairs are outer electrons too, so leaving them out hides some.
  8. Group 5 nitrogen usually forms three, so recheck it · Group 5 means three usual bonds, so five bonds needs rechecking.
Worksheet · LightMySky