Group I elements of modern periodic table are called — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

# Group I Elements Classification **Step 1: Identify Group I elements** Group I elements are: $Li, Na, K, Rb, Cs, Fr$ (and H, which is sometimes placed here) **Step 2: Analyze their electronic configuration** All Group I elements have **1 valence electron** in their outermost s-orbital: - $Li: 1s^2 2s^1$ - $Na: [Ne] 3s^1$ - $K: [Ar] 4s^1$ **Step 3: Determine their chemical behavior** - They easily lose 1 electron to form +1 cations - They are highly reactive metals - They show metallic character with low ionization energies **Step 4: Name classification** Group I elements are called **Alkali Metals** (excluding hydrogen): - Form strong alkaline solutions with water - Exhibit characteristic metallic properties - Show decreasing ionization energy down the group **Conclusion:** Group I elements are universally referred to as **Alkali Metals** because they react with water to produce alkaline hydroxides (e.g., $2Na + 2H_2O \rightarrow 2NaOH + H_2↑$).