Metals, Nonmetals, and Metalloids

Metals, Nonmetals, and MetalloidsMetals, Nonmetals, and Metalloids

Group TrendsGroup Trends

HydrogenHydrogenHydrogen is a unique element.Most often occurs as a colorless diatomic gas, H2.It can either gain another electron to form the hydride ion, H, or lose its electron to become H+:

2Na(s) + H2(g) 2NaH(s)2H2(g) + O2(g) 2H2O(g)

H+ is a proton.The aqueous chemistry of hydrogen is dominated by H+

(aq).

Group Trends for the Active MetalsGroup Trends for the Active MetalsGroup 1A: The Alkali MetalsGroup 1A: The Alkali MetalsAlkali metals are all soft, silvery, very reactive.Chemistry dominated by the loss of their single s electron:

M M+ + e-

Alkali metals react with water to form MOH and hydrogen gas:

2M(s) + 2H2O(l) 2MOH(aq) + H2(g)

Common Alkali Metals Lithium (Li)

battery anode material used as drugs to treat manic-depressive disorders.

(Lithiated Bib-Label Soda)

Sodium (Na) “Common/Table salt" (sodium chloride, NaCl), "soda

ash" (sodium carbonate, Na2CO3), "baking soda" (sodium bicarbonate, NaHCO3, "bicarb"), and "caustic soda" (sodium hydroxide, NaOH), are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries

sodium vapour is used in lamps for street lighting

Group Trends for the Active MetalsGroup Trends for the Active Metals

Group 2A: The Alkaline Earth MetalsGroup 2A: The Alkaline Earth MetalsAlkaline earth metals are harder and more dense than the alkali metals.The chemistry is dominated by the loss of two s electrons:

M M2+ + 2e-.Mg(s) + Cl2(g) MgCl2(s)2Mg(s) + O2(g) 2MgO(s)

Be does not react with water. Mg will only react with steam. Ca onwards:

Ca(s) + 2H2O(l) Ca(OH)2(aq) + H2(g)

Romans used mortars containing lime (CaO) mixed with sand; Egyptians used gypsum (CaSO4*2H2O) in plasters for their tombs.

Radium, from pitchblende (Curies, 1898)

Magnesium used in flares and pyrotechnics, including incendiary bombs. It

was used in flash photography, it is lighter than aluminum, and is used in alloys used for aircraft,

car engine casings, and missile construction Calcium

quicklime (CaO) is made by heating limestone (CaCO3) and changes into slaked lime, Ca(OH)2, on the addition of water. It is a cheap base for the chemical industry with many uses.

calcium from limestone is a component of Portland cement. Mixed with sand it hardens as mortar and plaster while taking up carbon dioxide from the air

the solubility of the carbonate in water containing carbon dioxide results in stalactites and stalagmites and hardness in water.

Boron group

Boron borax, Na2B4O7.10H2O is a water softener in

washing powders Aluminum

Cans, foils, utensils, industrial applications where a strong, light, easily constructed material is needed (eg. Space/aircraft)

the oxide, alumina, occurs naturally as ruby, sapphire, corundum, and emery, and is used in glass making and refractories

Preview: Carbon and its group

Buckminsterfullerene(Buckyball) Diamond

Graphite

Silicon* silica, as sand, is a principal ingredient of glass, a material with excellent mechanical, optical, thermal, and electrical properties * computer chips, and other important electronic components

Nitrogen Group

Nitrogen N2: most abundant gas in atmosphere Ammonia!, Liquid Nitrogen

Phosphorus: First isolated from urine; glowed in dark (phos: light;

phoros:bringing) used in the manufacture of safety matches,

pyrotechnics, incendiary shells, smoke bombs, tracer bullets, etc.

Fertilizers and pesticides

Group Trends for Selected NonmetalsGroup Trends for Selected Nonmetals

Group 6A: The Oxygen Group Group 6A: The Oxygen Group (Chalcogens)(Chalcogens)As we move down the group the metallic character increases (O2 is a gas, Te is a metalloid, Po is a metal).There are two important forms of oxygen: O2 and ozone, O3. Ozone can be prepared from oxygen:

3O2(g) 2O3(g) H = +284.6 kJ.Ozone is pungent and toxic.


Group 6A: The Oxygen GroupGroup 6A: The Oxygen GroupOxygen (or dioxygen, O2) is a potent oxidizing agent since the O2- ion has a noble gas configuration.There are two oxidation states for oxygen: 2- (e.g. H2O) and 1- (e.g. H2O2).SULFURSulfur is another important member of this group.Most common form of sulfur is yellow S8.Sulfur tends to form S2- in compounds (sulfides).*Sulfur: “brimstone”; GUNPOWDER: sulfur, KNO3, charcoal


Group 7A: The HalogensGroup 7A: The HalogensThe chemistry of the halogens is dominated by gaining an electron to form an anion:

X2 + 2e- 2X-.Fluorine is one of the most reactive substances known: 2F2(g) + 2H2O(l) 4HF(aq) + O2(g) H =

-758.7 kJ.All halogens consists of diatomic molecules, X2.


Group 8A: The Noble GasesGroup 8A: The Noble GasesThese are all nonmetals and monatomic.They are notoriously unreactive because they have completely filled s and p sub-shells.In 1962 the first compound of the noble gases was prepared: XeF2, XeF4, and XeF6.Another example: KrF2

Chemistry in Action: Discovery of the Noble Gases

Sir William Ramsay

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Metals, Nonmetals, and Metalloids