Molecular Compounds

Molecular Compound atoms of non-metals combine and form a pure substance example: nitrous oxide (N2O) the atoms are joined by covalent bonds each bond shares a pair of electrons bonded atoms form a MOLECULE

Covalent Bonds connection where two atoms share a pair of electrons the electron pair belongs to both atoms

CovalentBonding.notebook

Remembering Non-Metals non-metal valence shells are almost full the spaces can attract other electrons allows non-metals to get close to each other the two nuclei form strong attractions for each other’s electrons but not strong enough net effect – share the electrons

Molecular Elements molecular elements are two or more atoms of the same element a molecule made of only two atoms is called a diatomic molecule Molecular Elements that Commonly Form Diatomic Molecules: Element Formula bromine Br2 chlorine Cl2 fluorine F2 hydrogen H2 iodine I2 nitrogen N2 oxygen O2

Other Diatomic Molecules there can be other types of diatomic molecules some can share 2 pairs of electrons e.g. O2 other diatomic molecules can be made of two different elements e.g. hydrogen and fluoride HF

Properties of Molecular Compounds at room temperature they can be liquid, solid or gas generally soft solids if dissolved in water, they do not conduct electricity have relatively low melting points two non-metallic elements can combine in different ways and form different compounds e.g. hydrogen and oxygen: water = H2O hydrogen peroxide = H2O2

Naming Molecular Compounds any molecular compound that contains two elements and does not contain hydrogen uses Greek prefixes the prefix indicates how many atoms of each element are in the compound e.g. P2O5 is diphosphorus pentoxide di- means 2, pent- means 5

Number of Atoms Prefix 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa- 9 nona- 10 deca-

Naming Rules e.g. N2O Name the first element (e.g. nitrogen) Name the second element, using the suffix “-ide” (e.g. oxide) add prefixes to indicate the number of each atom (e.g. dinitrogen monoxide) Note: mono is not used in first element; if it is required before oxide, the last “o” in prefix is dropped e.g. N2O

Hydrogen hydrogen is unique often does not follow same naming has given names: Name Formula water H2O hydrogen peroxide H2O2 ammonia NH3 methane NH4 hydrogen sulfide H2S

REVIEW: Ionic and Covalent Bonds Ionic and Molecular Compounds.avi

SMARTBoard Naming Gizmo Link

Activity: Look at your cue card You need to find your match! Everyone’s card is either: first element in a molecular compound second element in a molecular compound the complete compound in either text or symbols