Question

Give a reason why hydrogen might be placed along with the group lA elements of the periodic table.

Short answer

Hydrogen might be placed along with group 1A elements of the periodic table because it shares a key property with them: having one electron in its outermost shell. Both hydrogen and group 1A elements tend to lose their single valence electron in chemical reactions, forming ions with a +1 charge. However, hydrogen has distinct properties that set it apart from alkali metals, making it unique in its behavior.

Step-by-step solution

Understand the properties of hydrogen and group 1A elements

Hydrogen is the first and the lightest element in the periodic table, and it has an atomic number of 1. It has only one electron, which is in the 1s orbital. Group 1A elements (alkali metals) include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). They all have one electron in their outermost shell (valence electron) and are highly reactive.

Explain the similarities between hydrogen and group 1A elements

Hydrogen shares some properties with the group 1A elements due to having one electron in its outermost shell which is similar to the alkali metals. Both hydrogen and group 1A elements tend to lose their single valence electron in chemical reactions. As a result, they typically form ions with a +1 charge (H⁺ in case of hydrogen and M⁺ for alkali metals). This is the primary reason why hydrogen could be placed along with the group 1A elements of the periodic table.

Highlight the differences between hydrogen and group 1A elements

Despite the similarities, there are some significant differences between hydrogen and group 1A elements. Hydrogen is a non-metal, while alkali metals are all metals. Hydrogen has a much lower density and a lower melting point and boiling point compared to alkali metals. Moreover, hydrogen can form diatomic molecules (H₂) while alkali metals do not. These differences make hydrogen unique and distinguished from group 1A elements. Overall, hydrogen shares some chemical properties with the group 1A elements due to the presence of a single valence electron in both cases. This is the main reason why hydrogen can sometimes be placed alongside the alkali metals (group 1A) in the periodic table. However, hydrogen also has distinct properties, which set it apart from the alkali metals, making it unique in its behavior.