Molecular Structure HONC if You Like Molecules Bonding

Molecular Structure: HONC if You Like Molecules Bonding Tendencies

Chem. Catalyst Examine these molecules. What patterns do you see in the bonding of atoms of hydrogen, oxygen, carbon, and nitrogen?

Key Question What are the rules for drawing structural formulas? You will be able to: • create accurate structural formulas from molecular formulas • identify and differentiate between isomers and molecules oriented differently in space • explain and utilize the HONC 1234 rule

Types of bonds…. Ionic- Metal with nonmetal Covalent – Nonmetal with nonmetal What about two metals? Metals do not combine with metals. They form alloys, which is a solution of a metal in a metal Examples: steel, brass, and bronze However Atoms of metal are still held together with…

Metallic Bond Metallic bond – bond found in metal; holds metal atoms together very strongly Formed between atoms of metallic elements Good conductors at all states, lustrous, very high melting points

What We Already Know Valence electrons are important because… They are the electrons in the outermost shell They are the same for each element in a group (column). Want to follow the octet rule of having 8 electrons in the outer shell. They are the electrons that are involved in bonding.

Discussion Notes The HONC 1234 rule is a way to remember the bonding tendencies of hydrogen, oxygen, nitrogen, and carbon atoms in molecules. Hydrogen tends to form one bond, oxygen two, nitrogen three and carbon four.

The HONC 1234 is an example of Octet Rule How many electrons would carbon want? gain 4 How many electrons would nitrogen want? gain 3 How many electrons would oxygen want? gain 2

Wrap Up What are the rules for drawing structural formulas? • The HONC 1234 rule indicates how many times hydrogen, oxygen, nitrogen, and carbon atoms tend to bond. • When a molecule is oriented differently in space, it is still the same molecule. • When trying to decide whether two structures represent the same molecule, you must check how the atoms are connected.

Check-In Will any of the molecules shown on the following slide have similar properties? Explain your thinking.