The Periodic Law Electron Configuration and the Periodic Table

The alkaline earth metals Mg + 2 H 2 O  Mg(OH) 2 + H 2 Ca + 2 H 2 O  Ca(OH) 2 + H 2 Be Ca Sr Ba Ra Mg

The Alkali Metals Sodium and Water – YouTube Na + H 2 O  NaOH + H 2 Potassium and Water – YouTube K + H 2 O  KOH + H 2 Li Na Cs Fr K Rb

Periods and Blocks of the Periodic Table Write the electron configuration for: Mg Ca F Cl 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 1s 2 2s 2 2p 5 1s 2 2s 2 2p 6 3s 2 3p 5

Sample Problems 1.Without looking at the periodic table, give the group, period, and block in which the element with the electron configuration [Xe]6s 2 is located. Group 2, sixth period, s-block 2.Without looking at the periodic table, write the electron configuration for the Group 1 element in the third period. Is this element likely to be more active or less active than the element in #1? 1s 2 2s 2 2p 6 3s 1 ; more reactive

Hydrogen and Helium Hydrogen and helium are the most abundant elements in the universe. Hydrogen makes up 76 % of the mass of the universe and helium makes up 23 %. Hydrogen1s 1 Despite the same outer configuration as the alkali metals, H has unique properties unlike any other group. Helium1s 2 Although its configuration is similar to the alkaline earth metals, it has the properties of a noble gas due to its filled outer energy level.

d-Block elements

d-Block elements are known as transition metals Have common metallic properties Conduct heat and electricity Less reactive than alkali and alkaline earth metals Some are very unreactive: Au, Pt, Pd, Ag

d-Block elements Deviations from orbital filling: Nickel (Ni):[Ar]4s 2 3d 8 Palladium (Pd):[Kr]5s 0 4d 10 Platinum (Pt):[Xe]6s 1 4f 14 5d 9 In each case the sum of s and d electrons is 10

d-Block elements Oxidation States Most transition metals are multivalent Iron (Fe):[Ar]4s 2 3d 6 Iron II (Fe 2+ ):[Ar]4s 1 3d 5 Iron III (Fe 3+ ):[Ar]4s 0 3d 5

p-Block elements p-Block and s-block elements together are known as the main group elements. Properties vary considerably Includes nonmetals, metalloids, and metals

p-Block elements Metalloids (semi-metals) B, Si, Ge, As, Sb, Te, Po?, At? Properties of both metals and nonmetals Brittle solids Conduct electricity Silicon

p-Block Elements Metals Al, Ga, In, Tl, Sn, Pb, Bi Reactive and found in nature as part of compounds Relatively stable in elemental form Softer and less dense than d-block metals. (Pb is an exception.)

p-Block Elements Halogens Group 17 nonmetals Very reactive; react with most metals to form salts one electron short of noble gas configuration Form -1 ions F Cl Br I At Uuo