Question

sal drew the electron dot diagram of an aluminum atom as shown. how should sal correct his diagram? he should add five more dots so that the atom obeys the octet rule. he should add ten more dots so that all thirteen electrons are shown. he should add a single dot below the symbol. he should add one dot below and one dot to the left of the symbol.

Explanation:

1. Recall electron dot diagram rules: Electron dot diagrams (Lewis dot structures) for atoms show valence electrons, not all electrons. Aluminum (Al) has 3 valence electrons (group 13, so 3 valence e⁻).
2. Analyze the given diagram: The current diagram has 2 dots (one above, one to the right). It needs 3 valence electrons. So we need to add one more valence electron dot. The positions for valence electrons are around the symbol: top, right, bottom, left. Currently, top and right have dots; bottom and left are empty. To distribute 3 valence electrons, after top (1) and right (1), we add one to bottom (or left). Wait, no—wait, Al has 3 valence electrons. Let's re - check:

• Valence electrons for Al: Atomic number 13, electron configuration \(1s^2 2s^2 2p^6 3s^2 3p^1\), so valence electrons (n = 3) are \(3s^2 3p^1\), total 3.
• The Lewis dot structure places valence electrons around the symbol, one on each side (top, right, bottom, left) before pairing. So for 3 valence electrons: first top (1), then right (1), then bottom (1) (or left). The current diagram has top (1) and right (1), so we need to add one more, which should be placed below the symbol (or left, but the option "He should add a single dot below the symbol" is an option). Let's analyze the other options:
• Option 1: Octet rule for atoms (not ions) in Lewis dot structures for main - group elements: For Al, as a metal, it tends to lose electrons, but the Lewis dot structure shows valence electrons. The octet rule for the atom's dot structure is about valence electrons? No, the octet rule for bonding, but the dot structure shows valence electrons. Al has 3 valence electrons, not 8, so adding 5 to make 8 is wrong (since it's valence electrons, not trying to fill octet in the dot structure for the atom itself; the dot structure shows valence electrons, not a filled octet for the atom).
• Option 2: Lewis dot structures show valence electrons, not all 13 electrons. So adding 10 more to show all 13 is wrong.
• Option 3: Add a single dot below the symbol. Since we have 2 dots (top, right) and need 3, adding one below (or left) is correct. Let's count: top (1), right (1), bottom (1) – that's 3 valence electrons, which matches Al's valence electrons.
• Option 4: Adding one below and one to the left would be 2 more dots, making total valence electrons 4, which is wrong (Al has 3).

Answer:

He should add a single dot below the symbol.