The alkali metals are a group of metallic elements that correspond to group 1 of the modern periodic table. The members of this group include lithium, sodium, potassium, rubidium, and caesium. Sometimes, even the element hydrogen is added to this group and considered as an alkali metal. The reason behind this is that hydrogen, like all other alkali metals, features valence electrons lying in an s orbital. Some important properties and applications of the alkali metals are provided in this article.
Properties of the Alkali Metals
The alkali metals are known to constitute the first group of chemical elements found in the periodic table of elements. Lithium, the first member of the alkali metals, corresponds to the atomic number 3 and is denoted by the symbol Li. Sodium, the second member of the alkali metals, corresponds to the atomic number 11 and is denoted by the symbol Na. The third alkali metal is potassium, which is denoted by the symbol K. The atomic number of potassium is 19. The fourth and fifth alkali metals are rubidium and caesium, corresponding to atomic numbers 37 and 55 respectively. Rubidium is denoted by the symbol Rb and caesium is denoted by the symbol Cs. All 5 of these elements are known to exist in the solid phase under standard conditions for temperature and pressure. It can be noted that all alkali metals are s-block elements.
Among all the alkali metals, caesium is known to be the most reactive. All alkali metals are known to readily participate in chemical reactions with water. It can also be noted that the heavier alkali metals like rubidium and caesium react in a very violent manner when exposed to water. Therefore, they must be stored in dry environments and must be kept away from moisture.
Applications of the Alkali Metals
Lithium and the compounds of lithium are known to have a wide range of applications in the production of batteries. Lithium is also known to have several other industrial applications, such as in the production of heat-resistant ceramics and glass. It is also used as a component of mood-stabilizing drugs for the treatment of bipolar disorders in Humans. Several sodium compounds are known to have high commercial value. Sodium chloride, or common salt, is widely used globally for cooking and for the preservation of food. Sodium bicarbonate is widely used in baking and is commonly known as baking soda.
Potassium compounds are known to have very high solubilities in water and are used industrially for the production of soap. Potassium is also a necessary nutrient for the growth of crops, which is the reason why potassium is widely used in the production of fertilizers for the agriculture industry. An interesting application of rubidium is in the fireworks industry, where it imparts a purple colour to the firework explosions.
One of the most popular applications of the element caesium is in the production of atomic clocks. It can be noted that the general electronic configuration of elements belonging to group 1 of the modern periodic table is ns1.