Lewis Dot structures

Lewis Dot structures

By James Klein

Multiple Choice

Which orbital are valence electrons in?

• Innermost orbital

• Middle orbital

• Outermost orbital

Multiple Choice

How many valence electrons do group 17 elements have?

• 17

• 7

• 16

• 6

Multiple Choice

How many valence electrons does Sodium (Na) have

• 1
• 8
• 7
• 3

Lewis Electron Dot Structure

The chemical symbol of an element is surrounded by a number of dots which are the valence electrons.

Rule of 8 (Octet rule)

​Elements form stable bonds when they have 8 valence electrons counted in the bond.

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The element Helium (₂He) is different. Since helium has 2 electrons, its energy level is complete with 2 valence electrons making it a stable element. That's why it is listed with the noble gasses, the rest of which have 8 valence electrons normally.

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Multiple Choice

Which is the correct molecular structure for carbon dioxide?