Chem Notes 1-13 Groups

 

 

Group 1: The Alkali Metals

 

Characteristics

• Do not occur in nature as elements
• Reactive metals that are obtained by reducing 1+ ions in natural compounds
• Stored under kerosene because they are highly reactive
• One valence electron
• Form ionic compounds
• Strong reducing agents and low ionization energies
• Good conductors of electricity and heat
• Ductile, malleable, can be cut with knife, silvery luster, low density, low melting point

 

Reactions:Look at the book Pg 729

 

Analytical Tests

• Easily detected by flame tests
• When sodium and potassium present in sample color of sodium masks color of potassium

Colors

Lithium	Red
Sodium	Yellow
Potassium	violet
Rubidium	Lavender
Cesium	Blue
francium	Not in Book

 

Application(Sodium Vapor Lighting)

• Sodium Vapor Lighting used for street lamps and other lights
• Very Bright and uses less energy
• Light Intensity per Watt for sodium vapor lamps beats everything else

 

Application Health(SEE TABLE ON PAGE 731)

• Two most important electrolyte solutes are K+ and Na+
• Facilitate transmission of nerve impules and control water retention of cells

·   Sodium ions mostly found in fluid outside cells and potassium ions found in fluid inside cells

·   Abnormal electrolyte concentration in  blood can indicate presence of disease

·   Active Transport allows cell to maintain electrolyte balance(Pg 732 diagram)

 

Group 2:Alkaline Earth Metals

 

Characteristics

• Do not occur naturally
• Most commonly occur as carbonates(phosphates,silicates,and sulfates)
• Occur naturally as compounds that are either insoluble or slightly soluble in H2O
• Have 2 valence electrons
• Consist of atom tending to lose 2 electrons per atom, forming 2+ ions
• Are less reactive than Group 1 metals
• Form ionic compounds primarily
• React with water to form bases and Hydrogen gas
• Good conductors of heat and electricity, ductile, malleable
• Silvery luster, includes naturally radioactive element Radium

 

Common Reactions(735)

Analytical Test: Flame Test(735 for colors)

 

Application Technology(Fireworks pg 736)

• Fireworks like fuse bombs
• Colors produced in much the same way as flame test
• Color of light depends n metal used
• Flares consist of finely divided magnesium metal and oxidizing agent
• When ignited reaction produces so much energy that glow given off

 

Application Health

• Calcium makes good portion of teeth and bone mass
• Small % of calcium used in reactions by which cells communicate and regulation of body processes
• If calcium level is low hormones signal release of ca from bone and signal gastrointestinal tract to absorb more calcium
• Osteoporosis is a disease characterized by decrease in bone mass
• Magnesium most important role is in absorption of calcium by cells
• Major component of bones
• Recommended intake for Ca(1000 mg/day), Mg(400 md/day)

 

 

 

 

 

 

 

 

 

 

 

Groups 3-12(Transition Metals)

 

Characteristics

• One or 2 valence electrons
• Harder and more brittle than previous groups(1-2)
• Good conductors of heat and electricity
• Malleable and ductile
• Silvery luster except copper and gold
• Includes lanthanides and actinides
• Include mercury(only liquid metal at room temp)
• Chemical properties differ from each other
• Tend to have 2 or more common oxidation states
• Often form colored compounds
• May form complex ions

 

Common Reactions(See Pg 741)

 

Analytical Test(See 742)

• Flame test does not work
• Use qualitative analysis

 

Application Geology

• Color of gemstone is determined by the presence of small amounts of the transition metals
• Auguste Verneuil found way to make artificial rubies

 

Application Tech

• Alloy is mix of a metal and one or more elements
• Alloys are stronger and superior properties
• Cast iron is mixture between pure iron and some carbon and other compounds
• 2 ways for alloys to crystallize(Interstitial and Substitutional) SEE PAGE 746 for pic

 

The Environment

• overexposure to mercury can damage kidney, heart, brain
• symptoms are numbness, tunnel vision, anemia and others
• Hg can be found in environment and food supply
• Body has some protective mechanisms to deal with trace amounts
• Present in fish a lot in US

 

Application Health

• Minerals are considered inorganic elements of body
• 2 types: major and trace
• trace are minerals are those with 100 mg or less of recommended intake
• Most iron is in hemoglobin
• Hemoglobin in red blood cells transports oxygen to cells and picks up carbon dioxide
• Iron in proteins of electron transport system and immune system

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Group 13 Boron Family

 

Characteristics

• Do not occur naturally in element form
• Scarce in nature
• Have 3 valence electrons
• Are metallic solids(except Boron which is solid metalloid)
• Soft and low melting point(except Boron which is hard and high melting point0
• Chemically reactive at moderate temperatures(except boron)

 

Common Reactions(751)

 

Analytical Test

• No simple test other than atomic absorption spectroscopy

 

Application Technology

·         Aluminum belongs to category of self protecting metals

·         These metals are oxidized when exposed to oxygen in air and form hard protective metal oxide on surface

·         This oxide protects underlying metal from further oxidation

·         Aluminum good conductor of electric current(better than copper)

·         Used to construct aircraft, boats and other stuff

·         Aluminum and its alloys are good conductors of heat