Lesson 4 of 8
Chemical Bonding
Atoms bond to become more stable. Most atoms want a full outer shell of electrons, and bonding is how they get there.
KEY TERM
The octet rule: atoms tend to gain, lose, or share electrons until they have eight electrons in their outer shell, like the stable noble gases.
Ionic Bonds
- ●One atom gives up electrons and another takes them.
- ●This usually happens between a metal and a nonmetal.
- ●The atoms become charged ions and stick together by opposite-charge attraction. Example: NaCl, table salt.
Covalent Bonds
- ●Atoms share electrons instead of giving them away.
- ●This usually happens between two nonmetals.
- ●Example: H2O, water, where oxygen shares electrons with two hydrogens.
REMEMBER
Ionic = transfer (give and take). Covalent = share. Metal plus nonmetal usually means ionic; nonmetal plus nonmetal usually means covalent.