Which element is not an alkali metal?

Understand the Problem

The question is asking to identify an element that does not belong to the alkali metals group in the periodic table. Alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium. The question requires knowledge of the periodic table to determine which given element is not part of this group.

More Information

Hydrogen, despite having one electron in its outermost shell like alkali metals, is not classified as an alkali metal because it is a gas and does not exhibit the same chemical properties.

Sources

• Hydrogen is not an alkali metal - Britannica - britannica.com
• Group 1: Hydrogen and the Alkali Metals - Chemistry LibreTexts - chem.libretexts.org