1. COMPOUNDS part two: molecular compounds

2. += Na Cl NaCl Reminder: Ionic compounds involve a metal IONIC COMPOUNDS and a non-metal

3. MOLECULAR COMPOUNDS Molecular compounds involve two or more non-metals. They contain covalent bonds where a pair of electrons is shared between two non- metal elements.

4. MOLECULAR ELEMENTS A molecular element is when two or more atoms of the same element are joined by covalent bonds. If 2 atoms of the same element – diatomic molecule.

5. MOLECULAR COMPOUNDS Both molecular elements and molecular compounds involve covalent bonds between non-metal atoms. For example, water is a molecular compound with 2 covalent bonds. Each hydrogen atom shares 1 pair of electrons with the oxygen atom.

6. PROPERTIES Molecular compounds have unique properties… Soft Low melting points Solutions do not conduct electricity

7. NAMING MOLECULAR COMPOUNDS For compounds not containing hydrogen: Name the first element Name the second element and change the ending of the name to “ide” Add prefixes to show the number of each atom

8. NAMING MOLECULAR COMPOUNDS Using prefixes: The prefix “mono” is not needed if there is only one atom of the first element When mono is put in front of oxygen, the second “o” is dropped (monoxide instead of monooxide)

9. Example Problem 1: Write the name of the molecular compound N 2 O 1.Name the first element: 2.Name the second element and change the ending: 3.Add prefixes to show the number of each atom: NAMING MOLECULAR COMPOUNDS N = nitrogen The atom is oxygen, therefore oxide Dinitrogen monoxide

10. Example Problem 2: Write the name of the molecular compound PBr 3 1.Name the first element: 2.Name the second element and change the ending: 3.Add prefixes to show the number of each atom: NAMING MOLECULAR COMPOUNDS P = phosphorous bromide Phosphorous tribromide

11. Example Problem 1: Write the chemical formula of the compound dinitrogen tetroxide NAMING MOLECULAR COMPOUNDS NONO N2O4N2O4 Therefore N 2 O 4 This cannot be simplified because it is a molecular compound.

12. NAMING MOLECULAR COMPOUNDS Hydrogen is unique in many ways. Therefore, many compounds containing hydrogen have been given simple, common names. For example, dihydrogen monoxide (H 2 O) is called water.