CBSE · Class 10 · Chemistry · Chapter 3

Metals and Non-Metals — Properties Focus — Formula Sheet

Board Formulas

7 formulas

1.Electron-Dot: Sodium Chloride★
$N a^{∙} +_{∙∙}^{∙∙} ∙∙ C l ∙∙^{∙} ⟶ N a^{+} [C l :]^{-}$
Na (2,8,1) donates 1e⁻ to Cl (2,8,7) — both attain the nearest noble-gas configuration.
2.Electron-Dot: Water
$H : O ¨ : H$
Covalent: each H shares 1 pair with O. O has 2 lone pairs. Bent (angular) molecule, 104.5° bond angle.
3.Electron-Dot: Methane
$H : H C H : H$
C shares 4 electron pairs with 4 H atoms — tetrahedral geometry.
4.Reactivity Series (Compact)★
$K > N a > C a > M g > A l > Z n > F e > P b > (H) > C u > H g > A g > A u$
Memorise once and for all. Determines who displaces whom, and whether the metal reacts with water / acid.
5.Metal + Non-metal (Ionic)
$2 N a + C l_{2} ⟶ 2 N a C l$
Ionic compounds — high m.p., soluble in water, conduct in molten/aqueous form.
6.Non-metal + Non-metal (Covalent)
$H_{2} + C l_{2} ⟶ 2 H C l$
Covalent compounds — low m.p., mostly insoluble in water, do not conduct electricity.
7.Amphoteric Oxide Test
$A l_{2} O_{3} + H C l, N a O H ⟶ both react$
An oxide is amphoteric if it dissolves in BOTH acid and base. Common examples: Al₂O₃, ZnO, PbO, SnO.