Chapter 4 Continued... 4.4 Coordinate Covalent Bonds ● A coordinate covalent bond is the covalent bond that forms when both electrons are donated by the same atom. ● See colorful graphic on page 108 ● Once formed, no different from any other covalent bond ○ Result in unusual bonding patterns ○ Nitrogen with 4 covalent bonds +¿ ○ Oxygen with 3 bonds ( H 3 ¿ ) O ● See graphic at very bottom of page 108 Remember: metals form ionic compounds (giving up), non­metals form covalent (sharing) 4.5 Characteristics of Molecular Compounds ● Ionic compounds­ high melting and high boiling points ○ Attractive forces between oppositely charged ions are so strong. ● But….Molecules are neutral ○ No strong attraction to hold them together. ● And….Weaker forces exist between molecules, called intermolecular forces ● Very weak intermolecular forces = gas ● Somewhat stronger intermolecular forces = liquid ● Strongest = molecular solid ● Molecular solids ○ Lower melting and boiling points than ionic compounds ○ Rarely soluble in water ○ Do not conduct electricity when melted ● See table 4.1 on page 110 ● Molecular formula