An element (except hydrogen) in group 1 of the periodic table is an alkali metal. The alkali metals are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). All group 1 elements contain one electron in their valence shell (outer electron orbital), which they tend to lose. Due to this, group 1 elements share common characteristics. They ionically bond with elements from group 17 to form compounds such as table salt (NaCl). Alkali metals react vigorously with oxygen and water. As you go down the alkali metal group, the elements become more reactive, and their melting points decrease. Rubidium is extremely reactive and is handled with caution due to its high reactivity. Alkali metals are generally soft to the touch. For example, it is possible to cut a block of sodium with a table knife. Rubidium and caesium have fewer commercial applications than other alkali metals.Various compounds of lithium, sodium, and potassium are commonly found in nature. Rubidium, caesium, and francium are rarer in nature. Metallic lithium, sodium, and potassium and their various chemical compounds have multiple commercial applications and can be recovered from their compounds using electrochemical methods. For example, a Downs cell produces metallic sodium from molten sodium chloride. Molten sodium metal forms within the cell and is then recovered.
Downs Cell for Sodium Production
Beryllium is rare on Earth. Beryllium is commonly extracted from the mineral beryl using water and oxygen in a complex chemical process. Magnesium is abundant on Earth and is often alloyed with zinc or aluminum and used as structural components found in cars and aircraft. Magnesium can be extracted from magnesium minerals. It can also be extracted from seawater using electrochemical methods.
Calcium is also very abundant in nature and is used in the production of steel and cement. Strontium is another element abundant on Earth that was widely used in cathode ray tubes (CRTs) and vacuum tubes. Barium is present in small percentages on Earth and seawater and is extracted from the mineral barite. Radium is the heaviest alkaline earth metal and is radioactive. Radium is found in uranium and thorium ores. Small amounts of radium are used in medicine.Aluminum, found in group 13, is a soft metal with low density. Aluminum alloys are widely used as structural metals. Aluminum is utilized in construction and in packaging, such as production of aluminum cans. Electrochemistry is one method aluminum can be extracted from minerals. The mineral alumina (Al2O3) is dissolved in molten cryolite (Na3AlF6), which is another mineral. Molten metallic aluminum forms and settles at the bottom of the cell, the container where the process is taking place. The aluminum is then recovered. This process takes place at temperatures over 1,000°C and requires a lot of energy.