Element Electron Orbitals/Emission Spectrum Common Compound(s)/Application(s)
1
Hydrogen (H)
Water (H2O)/Ubiquity
Acid/Increasing H+ in Solvent
Base/Increasing OH- in Solvent
~/Stars' Burning Fuel
3
Lithium (Li)
~ Hydroxide (LiOH)/Soap
~ Carbonate (Li2CO3)/Industrial App.
~/Batteries, Heat-transfer Material, Thermal Nuclear Bomb
11
Sodium (Na)
~ Chloride (NaCl)/Table Salt
~ Hydroxide (NaOH)/Common Base
~/Heat-transfer Material, Reducing Agent1
19
Potassium (K)
~ Carbonate (K2CO3)/Fertilizer (Potash)
~ Sulfate (K2SO4)/Fertilizer (Potash)
~ Chloride (KCl)/Salt Substitute
~/Nervous Signal Transmission
37
Rubidium (Rb)
~/Cheap Atomic Clock, Interacting with unwanted gas to attain high vacuum (Getter)
55
Cesium (Cs)
~ Iodide (CsI)/Radiation Detector
~/Atomic Clock, Getter
87
Francium (Fr)
All its 30 known isotopes are radioactive, the one exists in nature has a half-life of 21 min. It is estimated that the Earth's crust contains less than one ounce of the substance

Group 1 Elements

1Reduction can be defined as the "loss of oxygen". For example, rust (oxide of iron or Fe2O3) can be reduced back to iron in blast furance via the reaction: 2Fe2O3 + 3C 4Fe + 3CO2. The carbon (coke - a fairly pure form of carbon) is the reducing agent, which is being oxidized in the process. Thus, another definition for reduction is to gain electron(s) by the atom; while oxidation is the loss of electron(s) from the atom. Note that the number of electrons associated with the oxygen atom remains the same, there is no loss or gain - it only oxidizes different atoms in the process.