Knowing the valency (combining capacity) of common ions is essential for writing correct chemical formulas in Class 9 and 10 Chemistry.
Sodium (Na): +1
Calcium (Ca): +2
Ammonium (NH₄): +1
Nitrate (NO₃): −1
Sulphate (SO₄): −2
Monovalent (Valency = 1):
Divalent (Valency = 2):
Trivalent (Valency = 3):
Example: Write the formula of Calcium Nitrate.
The valency of sulphate (SO₄²⁻) is −2 (divalent anion).
The valency of ammonium (NH₄⁺) is +1 (monovalent cation).
First 30 Elements of the Periodic Table — Names and Symbols
Learn the first 30 elements of the periodic table with names, symbols, and atomic numbers. Complete list for Class 10 and 11 Chemistry with memory tricks.
First Order Reaction Formula and Kinetics
Learn the mathematical formula for a first-order chemical reaction. Understand the integrated rate law, the rate constant (k), and the half-life equation.
Fitkari ka Formula (Chemical Formula of Alum)
Find the chemical formula of Fitkari, also known as Potash Alum. Learn its chemical name and common uses in water purification and shaving.
What is a Flame Photometer?
Learn about the Flame Photometer in analytical chemistry. Understand its principle, working, and how it is used to measure Sodium and Potassium in medical blood tests.
A Football Bladder Contains Equimolar Amounts of Gases — Dalton's Law
A football bladder contains equimolar amounts of nitrogen and CO₂. Using Dalton's Law: partial pressure of each gas = total pressure × mole fraction. Class 11 Chemistry.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.