Question

Give a reason why hydrogen might be placed along with the group 1 A elements of the periodic table.

Short answer

Hydrogen is placed along with Group 1A elements in the periodic table due to its similar electron configuration and chemical reactivity. Both hydrogen and Group 1A elements have one electron in their outermost energy level and tend to lose this electron to form a +1 charged ion during chemical reactions.

Step-by-step solution

Understanding the Periodic Table and Group 1A Elements

In the periodic table, elements are arranged according to their atomic number and similar properties. Group 1A elements, also known as alkali metals, include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). These elements have a common characteristic: they all have one electron in their outermost energy level (valence electron).

Identifying Hydrogen's Electron Configuration

Hydrogen (H) is the first element in the periodic table, with an atomic number of 1. Its electron configuration is 1s^1, meaning that it has one electron in its outermost energy level (the 1s orbital), just like the other Group 1A elements.

Discussing the Similarity in Chemical Reactivity

Hydrogen and other Group 1A elements share similar chemical reactivity due to having one valence electron. Elements in this group tend to lose their single valence electron readily to achieve a stable electron configuration. This results in the formation of a positive ion (cation) with a +1 charge. Therefore, hydrogen resembles the group 1A elements in its reactivity and tendency to form +1 charged ions. To summarize: Hydrogen might be placed along with the Group 1A elements of the periodic table because it shares similar electron configuration and chemical reactivity with these elements. Specifically, hydrogen has one electron in its outermost energy level like alkali metals and tends to lose this electron to form a +1 charged ion during chemical reactions.