BONDING

 

• Recall that substances bond in order to lower their potential energy
• Elements will lower their potential energy by gaining/losing/sharing their outer electrons until all electrons are paired up

 

Ionic Bond

 

• It is the electrostatic force of attraction between oppositely charged ions formed when the metal loses its outer electrons forming a positive ion
• The non-metal gains these outer electrons to obtain a full outer shell and forms a negative ion
• Things formed by ionic bonds tend to conduct electricity ONLY when dissolved or if in the molten state

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Beryllium will lose its 2 outer electrons to become a +2 ion with a noble gas electron structure

Pure Covalent Bond

 

• Both atoms are attracted to the same pair of shared electrons
• This type of bond occurs between two non-metals
• The electrons are equally shared between the two atoms (ΔE’neg ≤ 0.4)
• Compounds formed by all types of covalent bonds do not conduct electricity as a solid, liquid or when dissolved

 

 

 

 

 

 

 

 

Polar Covalent Bond

 

• Appears as an unequal sharing of electrons (ΔE’neg > 0.4)
• The more electronegative atom will pull the pair of electrons towards it creating a slightly positive (δ+) end and a slightly negative (δ-) end.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Coordinate Covalent Bonds

 

• Forms when one of the atoms donated both of its electrons to be shared with another atom
• Once formed, there is no difference between this and the other covalent bonds