Physical Science / Unit 4: Chemical Bonds and Compounds
4.1 Why Atoms Bond
Notes
Atoms bond to become more stable, usually by getting a full outer energy level.
- The octet rule: atoms tend to gain, lose or share electrons to have 8 valence electrons (2 for hydrogen and helium).
- Noble gases already have full outer levels, so they rarely bond.
- A chemical bond is the attraction that holds atoms together.
- An electron dot diagram shows valence electrons as dots around the element symbol.
Practice
Why do most atoms form chemical bonds?
A full outer level is a stable arrangement.
Which element is least likely to form bonds?
Neon is a noble gas with a full outer level.
How many dots would an electron dot diagram of nitrogen (Group 15) show?
Group 15 elements have 5 valence electrons.
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