When s and p block elements react, the bond formed is

Step 1: Analyze the question The question asks what type of bond forms when an s-block element (e.g., Na, K, Mg, Ca) reacts with a p-block element (e.g., Cl, O, S, N).

Step 2: Explain the concept

• s-block elements (Groups 1 and 2) are metals with low ionization energies, so they easily lose their valence electrons.
• p-block elements on the right side of the table (Groups 15-17) are non-metals with high electronegativity, so they readily gain electrons.
• When electrons are transferred from the metal to the non-metal, oppositely charged ions form and are held together by electrostatic attraction. This is electrovalent (ionic) bonding.

Step 3: Work through an example Sodium (s-block) reacting with chlorine (p-block):

• Na → Na⁺ + e⁻ (loses 1 electron)
• Cl + e⁻ → Cl⁻ (gains 1 electron)
• Na⁺ and Cl⁻ attract to form NaCl, an ionic compound.

Likewise, Mg (s-block) + O (p-block) gives Mg²⁺ and O²⁻, forming MgO.

Step 4: Eliminate the other options

• B. Covalent: involves sharing of electrons, typically between two non-metals (p-block with p-block).
• C. Metallic: occurs between atoms of metals only, in a lattice of positive ions and delocalized electrons.
• D. Dative-covalent: one atom donates both electrons of the shared pair (e.g., NH₄⁺), which is not the typical s-p reaction.

Answer: The bond formed is electrovalent, which is option A.

Exam tip: Remember "metal + non-metal = ionic (electrovalent)", and "non-metal + non-metal = covalent". The s-block is mostly metals and the right-hand p-block is non-metals, so s + p usually means electron transfer. (A few exceptions, like BeCl₂, show covalent character, but WASSCE expects electrovalent here.)