Metals, Non Metals And Oxidation

Periodic Table

Metals, Non-Metals, Groups and Periods

Metals

• Metals are located left of the black line on the periodic table.

• Metals become cations, they lose electrons. Positive charge.

• Metals are maleable and ductile and they are also conductors of heat and electricity.

Non-Metals

• Located right of the black line on the periodic table.

• Non-Metals gain electrons and become negatively charged.

• Not conductors, brittle (if solid), not ductile.

Metaloids

• Located along the line on the periodic table.

• Share properties of metals and non-metals.

• Typically used in electronics.

Groups

• Group IA has a +1 charge, lose 1 electron. Also known as the Alkali Metals.

• Soft and white and highly reactive.

• Group IIA has a +2 charge, lose 2 electrons. Also known as the Alkaline Earth Metals. React easily with the halogens to form salts.

More Groups

• Group VIIA has a -1 charge. They gain one electron. This group is known as the halogens. Highly reactive, fluorine is one of the most reactive elements in existence.

• Group VIIIA are known as the Noble Gases. Full valence electron shell. Non-reactive. Important for use in welding, lighting, and space exploration.

Oxidation-Reduction

• Oxidation is the losing of an electron in a reaction. Original meaning was combining with oxygen.

• Reduction is the gaining of an electron in a reaction. Original meaning was removing oxygen.

• LEO says GER or OIL RIG

Examples of Oxidation

Examples of Oxidation

Reduction

Oxidation Characteristics

• Complete loss of electrons

• Shift of electrons away from an atom

• Gain of oxygen

• Increase in oxidation number

Characteristics of Reduction

• Complete gain of electrons

• Shift of electrons toward an atom

• Loss of oxygen

• Decrease in oxidation number

Rules for Assigning Oxidation #’s

• 1. Oxidation number of a monatomic ion is equal to its charge. Ex: Br1- is -1 and Fe3+ is +3.

• 2. Oxidation number of hydrogen in a compound is +1, except in metal hydrides like NaH then it is +1.

• Oxidation number of oxygen in compounds is -2.

continued

• 4. The oxidation number of an atom in an uncombined elemental form is 0.

• 5. For any neutral compound the sum of the oxidation numbers must equal zero.

• For a polyatomic ion, the sum of the oxidation numbers must equal the ionic charge of the ion.

Trends in Atomic Radius

Octet Rule

• Atoms, gain or lose electrons so they have 8 electrons in their outer shell.

• Think in terms of the Noble Gases.

• Electron configurations will be extremely important to understand here.

• The s and p sublevels must be full!!!

Octet Rule

• Na is in Group IA. It becomes Na+.

• Na has 11 electrons, 1 valence electron. Valence electrons are in the outer most shell.

• If Na+ has one less electron, it now has 10. Which element has 10 e? Neon

Octet Rule

• Magnesium has 12 electrons. It is in group IIA. Its oxidation number is +2.

• Mg becomes Mg2+

• It loses 2 e- and now has 10 electrons, it has 8 valence electrons, just like neon.

• Mg2+ electron configuration is:• 1s2 2s2 2p6

• Neon’s configuration is 1s2 2s2 2p6

Octet Rule

• Fluorine becomes F-

• Fluorine has 7 electrons in the valence shell. Gaining one electron gives it 8.

• It now has 10 total e-, just like neon.

• What is the electron configuration for this ion?

Octet Rule

• The “A” Group numbers refer to the number of valence electrons.

• Group IA has 1.• Group IIA has 2.• Group IIIA has 3.• All the way to group VIIIA which has 8.• You cannot go higher than VIIIA.

Oxidation Numbers

• For each e- the atom loses, your number is +1. For example, Group IA is +1, Group IIA is +2.

• For each e- the atom gains, your number is -1. For example, Group VIA is -2, Group VIIA is -1.

Oxidation Numbers

• The oxidation numbers of a neutral compound must equal 0.

• For example, Na+ must combine with something that will have a -1 charge.

• Na+ + Cl- NaCl• (+1) + (-1) =0• Mg2+ + S2- MgS• (+2) + (-2) = 0