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Teacher Lecture Notes
6-1 Reactive Metals: s block elements
The most reactive metals are group 1 and 2, the alkali and alkaline earth
metals.
Alkali Metals- (Group 1) Li, Na, K, Rb, Cs, and Fr. Arabic for ashes.
Properties-very reactive never found as a pure element. In addition to the
metal properties they also have low densities and low melting points. Soft and
easily oxidize (react with oxygen) and tarnish, they also react with water.
Stored in vacuums or oil. Why are the alkali metals the most reactive
metals? Reactivity is based on the valence shell electrons. How many
electrons does group 1 have in the valence shell?
Reactivity increases as you move down a group. Why do you think that is so?
What makes it easier to lose a valence electron? Think!
Who would members of group 1 be most likely to form an ionic bond with?
Sources and Uses- Na and K most abundant. Why? Both are water soluble
and found in oceans (NaCl table salt). Na is prepared commercial by
electrolysis to form NaOH (sodium hydroxide), NaOCL (bleach), NaHCO3
(baking soda). LiCO3 (lithium carbonate) is used to treat manic depression.
Alkaline Earth Metals-Group 2. Name from middle ages referring to the fact
that these metal oxides were unchanged by fire (earth, wind, fire and water)
Properties-Not as reactive as alkali but also not found in elemental state.
Higher densities, melting points and ionizing energies than alkali. Why?
Think about that Atomic Radius! Do react with water and oxygen. Because
the have two valence electrons they will form a 2+ ion and bond 1:1 with O2and it's family (XO) for example MgO....or with 1:2 halogens with a 1- charge
for each alkaline (XH2) for example MgF2. Be has some properties quite
different than others in this family
Sources and Use s-The most abundant are limestone (CaCO3) and magnetite
(MgCO3) mineral deposits. The most commonly used alkaline is Mg which is
recovered from seawater and mineral deposits, combined with Al to form a
super strong alloy (two or more metals combined). Mg will burn and is the
least reactive in its family. Why? Magnesium hydroxide (Mg(OH)2) is a
common antacid
Student Lecture
Notes
6-1 Section Review
1. What important characteristic do both alkali and alkaline earth metals
share?
2. Why are the alkali metals very reactive?
3. What are some common uses of the alkali and alkaline families?
4. Compare and contrast the Group 1 and 2 atoms and ions.
6-2 Transition Metals: d block elements
Properties/uses-living organisms require these, they are strong and used for
structural materials
Chromium (Cr)-hard silvery metal used to plate bumpers, resistant to
corrosion (reaction between metal, water, oxygen or an acid). Stainless steel is
an alloy that has a Cr coating. Color a common feature for elements between
d1 to d9. Cr3+ ion is used in paints.
Iron(Fe)- with carbon forms strong alloy steel. Elemental form corrodes to
form iron oxide (rust). Colored. Gives rusty red color in red blood cells.
Coinage Metals- (Cu, Ag & Au) found in elemental state and resist corrosion
because? First metals known to man. Tin with copper forms bronze. Less
abundant than many other metals. Does this influence value?
Copper (Cu)-soft reddish color, ductile, malleable used for electric wires and
pipes
Silver (Ag)-lustrous, soft white metal, better conductor than copper. Most
jewelry only contains 7.5% copper, it's actuarially an alloy, real silver would
be too soft. Also used in photography. Does tarnish
Gold (Au)-dense, soft, lustrous yellow metal. 24K is pure gold, jewelry is
alloyed to be 18K (75% gold) or less. Ag and Au alloy is yellow, Au and Ni is
white.
6-2 Section Review
1. Name, give the symbol and uses of two transition metals
2. What is an alloy? Name three important alloys in the transition metals.
3. Why are compounds containing Cu 2+ ion colored, while those containing
Cu1+ ion are not?
6-3 Inner Transitions- f block
4f- lanthanides after La. All soft silvery and most form 3+ ions because of a
[Xe] 6s2 5d1. Less reactive than alkaline, but too reactive to use for structures.
Used for color in TV's. Ce has a [Xe] 6s2 4f1 5d1.
5f-actinides after Ac. All radio active. Only thorium and uranium occur in
nature. Any element past U is artificial produced by bombardment.
6-3 Section Review
1. Where are the lanthanide's and actinides found on the PT?
2. Which elements in the actinides are artificial?
3. Why would Ce form a 4+ ion, whereas most other lanthanides form a 3+
ion?
6-4 From Metals to Nonmetals
Boron Group (13 or 3A) ns2 np1 electron configuration. They form 3+ ions
Al is third most abundant element on earth crust, most is combined as
aluminum oxide (Al2O3). Low density, when alloyed very strong lightweight
alloys result. Second most commonly produced and consumed metals. Name
a few ways you know it's used. (Who's the first most produced?)
Carbon Group (14 or 4A) ns2 np2 Carbon is a nonmetal, silicon and
germanium are semimetals (metalloids) tin and lead are metals.
Carbon (C)-very common on earth's crust, fossil fuels, common compound
material in living organisms. Pure forms diamonds and graphite. Carbons
combined with hydrogen are called hydrocarbons (dah) fossil fuels and gas
used to manufacture plastics as well as burning. If burned with limited supply
of Oxygen the form CO, colorless, odorless poisonous gas. What is produced
when plenty of oxygen is on hand? You probably had some today or
yesterday.
Silicon (Si)-second most abundant on earth's crust as silicon oxide SiO2 .
Principal element in sand use to make glass, semiconductor for transistors and
solar cells. To make colored glass what elements are added?
Germanium, Tin and Lead. (GE Sn Pb) Tin and lead the most common, Sn
used for tin cans, Pb Latin for plumbum (plumber) used in their pipes for
plumbing. Used today in batteries. Ge used in electronics
Nitrogen Group (15 or 5A)
N & P (nm), As & Sb (sm), Bi (m)
Nitrogen (N) 80% of atmosphere, colorless, odorless gas N2 generally not
reactive and cannot be used by living organisms until they have been nitrogen
fixated. Manufactured as fertilizer and clearer (NH3)
Phosphorus(P)-found in bones, used in fertilizers, detergents and in low doses
makes drinks bitter.
Oxygen Group (16 or 6A) O, S Se (nm), Te (sm), Po (m)
Oxygen (O)- most abundant element on earth. O2 odorless, colorless tasteless
gas. Elements that combine with oxygen are called oxides. It required for
respiration and combustion rxns (burning). O3 is ozone considered
dangerous as a pollutant in our atmosphere, however in the upper atmosphere
it blocks high energy radiation from the sun!
Sulfur (S)-occurs in elemental form (brimstone-rotten eggs, skunks) and fools
gold. Added to natural gas. Most common use is sulfuric acid (H2SO4)
Halogen Group (17 or 7A) (nm) At (sm)
Never found in elemental state. Why? Latin for salt. The halogens form salts
when combined with most metals. Their negative ions are called halides. All
are diatomic gases (di=two) two of the same atom bonded, except Br is a
liquid at room temp.
Fluorine (F)- Corrosive, most reactive of all elements. Why? CFC's
Chlorine (Cl)-most industrially useful. Salts, PVC.
Bromine (Br) Iodine (I)-less abundant, not widely used. Liquid at room temp.
Noble Gas Group (18 or 8A) (nm)
Least reactive. Xe can react with one element. Who? Why? Most abundant
is Ar, 1% earth's atmosphere, used as insulator, light bulbs. He most
commercially important, used for experiments at low temps, boils at -269C.
Ne used as red light. Is the weather ball all neon gas?
6-4 Section Review
1. List the most important p block elements.
2. What properties of Al make it an important commercial metal?
3. Why are group 18 (8A) known as the noble gases?
6-5 Hydrogen: One of a kind
Hydrogen (H) colorless, odorless, diatomic gas. Not found much in the
atmosphere. Why? Most of earth's hydrogen is found bonded to what? Most
abundant element in the universe. Combined with what organic (living)
compounds. Also found in hydrocarbons (fuels). Major use in fertilizers
(NH3)
6-5 Section Review
1. What are the sources of hydrogen on earth?
2. What is the major use of hydrogen?
3. Compare and contrast hydrogen to the
a. Alkali metals
b. Halogens
Special Notes
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