Which of the following trends is observed in Group 1 (alkali metals) down the group?
A. Electronegativity increases
B. Atomic radius increases
C. Ionization energy increases
D. Reactivity decreases
Answer: Option B
Solution (By JKExamLibrary)
Down Group 1 (Li → Fr), atomic radius increases due to addition of electron shells. Ionization energy and electronegativity decrease. Reactivity with water increases because the outer electron is more easily lost. Density generally increases, melting/boiling points decrease. Cesium and francium are most reactive. The increase in radius is due to principal quantum number increase.
Explanation:
Chlor-alkali process: electrolysis of concentrated NaCl solution (brine) yields NaOH, Cl₂, and H₂. Solvay process makes Na₂CO₃; Haber for NH₃; Contact for H₂SO₄.
Explanation:
Sodium (Na) is a soft, silvery-white alkali metal (Group 1). It is highly reactive, conducts electricity, and is malleable. Sulfur and phosphorus are non-metals; chlorine is a non-metal halogen gas. Sodium is never found free in nature; it is stored under kerosene to prevent reaction with air/moisture. It reacts vigorously with water, producing NaOH and H₂.
Explanation:
Magnesium loses two electrons to achieve noble gas configuration (Mg → Mg²⁺), so its electrovalency is +2. In MgCl₂, Mg²⁺ and two Cl⁻. Electrovalency is the charge on the ion. Covalency is number of covalent bonds. For Group 2 metals, electrovalency is always +2 (loss of 2 electrons).
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