In the periodic table, what are the elements called in the first column?

The elements in the first column of the periodic table are known as alkali metals. This group consists of very reactive metals that include lithium, sodium, potassium, rubidium, cesium, and francium. Alkali metals have one electron in their outermost shell, which makes them highly reactive, especially with water, where they can form strong bases and release hydrogen gas.

Their place in the periodic table reflects their similar chemical properties, including their typical formation of +1 ions, their softness compared to other metals, and the low melting points they exhibit. This unique reactivity occurs because the single valence electron is easily lost, allowing them to participate in various chemical reactions. Each alkali metal becomes more reactive as you move down the group due to the increasing atomic size and the corresponding decrease in the effective nuclear charge experienced by the outer electron.