Alkali metal

Alkali metals are a group of chemical elements from the s-block of the periodic table. They include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). These metals have similar properties, including their shiny, silvery-white color, softness, and high reactivity.

Characteristics

Alkali metals are highly reactive due to their single electron in their outer shell. This characteristic makes them more likely to engage in chemical reactions, often donating their valence electron to achieve a stable electron configuration. As a result, alkali metals are found in nature only in salts and other compounds.

Individual Alkali Metals

Lithium

Lithium is the lightest of the alkali metals and has the symbol Li. It is used in a variety of applications, including batteries and mental health medication.

Sodium

Sodium is a soft, silvery-white, highly reactive metal. It is an essential element for all animals and some plants.

Potassium

Potassium is a crucial nutrient for plants and animals. It is also used in fertilizers and as a salt substitute.

Rubidium

Rubidium is a soft, silvery-white metallic element of the alkali metal group. It is used in photoelectric cells and as a getter in vacuum tubes.

Caesium

Caesium is a soft, gold-colored alkali metal. It is used in atomic clocks and as a catalyst promoter.

Francium

Francium is a highly radioactive metal, and it is the heaviest known alkali metal.

Reactivity

The reactivity of alkali metals increases down the group. This is due to the increase in atomic size, which results in the outermost electron being further from the nucleus and therefore less tightly held, making it easier to lose and thus increasing reactivity.

Uses

Alkali metals have many uses, from industrial applications to biological roles. For example, sodium and potassium are essential for life, while lithium is used in batteries and mental health medication.