s-Block elements are a group of chemical elements found in the first two columns of the periodic table. This group includes the alkali metals (like lithium, sodium, and potassium) and the alkaline earth metals (such as magnesium and calcium). These elements are characterized by having their outermost electrons in the s orbital, which makes them highly reactive, especially the alkali metals. The s-block elements typically have low melting and boiling points, and they tend to form ionic compounds. They readily lose their outermost electron(s) to form positive ions, known as cations. Due to their reactivity, they are usually found in nature combined with other elements rather than in their pure form.