Metals and Non-metals | Class 10 Science Notes

3.3 HOW DO METALS AND NON-METALS REACT?

This section explains the chemical basis of metal and non-metal reactions using electronic configurations. Metals tend to lose electrons to attain a stable electronic configuration similar to noble gases, forming positive ions (cations). Non-metals tend to gain electrons to complete their valence shells, forming negative ions (anions). For example, sodium (Na) has one electron in its outermost shell and loses it to form Na⁺, while chlorine (Cl) has seven electrons in its outermost shell and gains one to form Cl⁻. The oppositely charged ions attract each other by strong electrostatic forces, forming ionic compounds like sodium chloride (NaCl). The section also discusses magnesium chloride (MgCl2), where magnesium loses two electrons to form Mg²⁺ and two chloride ions form Cl⁻ each. These ionic compounds are aggregates of ions held together by ionic bonds, not discrete molecules. The section introduces the properties of ionic compounds: they are solid, hard but brittle, have high melting and boiling points, are soluble in water but insoluble in organic solvents, and conduct electricity in molten or aqueous states but not in solid form. These properties arise from the strong electrostatic forces between ions and their mobility in molten or solution states.

📊 Diagram: Figure 3.5 Formation of sodium chloride; Table on page 11 (16×7); Figure 3.7; Figure 3.8; Table on page 12 (6×3)

🧪 Activity: Activity 3.13 involves heating salt samples, testing their solubility, and electrical conductivity of their aqueous solutions.

🔗 Connection: Leads to the occurrence of metals and their extraction from ores.

Table on page 11 (16×7)

Table on page 12 (6×3)