L-2 SIGNIFICANT FIGURES || SOME BASIC CONCEPTS OF CHEMISTRY || JEE MAINS || NEET CBSE ICSE BOARDS скачать в хорошем качестве

L-2 SIGNIFICANT FIGURES || SOME BASIC CONCEPTS OF CHEMISTRY || JEE MAINS || NEET CBSE ICSE BOARDS

#neet #chemistry #jee #somebasicconceptofchemistry #neet2026 #jeemains Significant Figures Sig Figs Definition: Significant figures are the digits in a number that carry meaning about its precision. They include: ✔ All non-zero digits ✔ Zeros between non-zero digits ✔ Trailing zeros after decimal ✔ Leading zeros never significant ⭐ Rules for Counting Significant Figures 1. All non-zero digits are significant Example: 345 → 3 sf 71.9 → 3 sf 2. Zeros between non-zero digits are significant Example: 105 → 3 sf 1008 → 4 sf 3. Leading zeros are not significant (These zeros only show the position of decimal) Examples: 0.05 → 1 sf 0.00720 → 3 sf 0.000402 → 3 sf 4. Trailing zeros in a number with a decimal are significant Examples: 20.0 → 3 sf 0.500 → 3 sf 48.700 → 5 sf 5. Trailing zeros without a decimal are not significant Examples: 200 → 1 sf 3000 → 1 sf 2500 → 2 sf 6. Exact numbers have infinite significant figures Examples: 100 students (counting) 12 eggs in a dozen Conversion factors: 1 m = 100 cm → ∞ sf ⭐ Rules for Calculations A. Multiplication & Division The final answer should have the same number of significant figures as the number with the least significant figures. Example: 4.62 × 3.1 Least sf = 2 Answer = 14 (2 sf) B. Addition & Subtraction The final answer should have same number of decimal places as the number with the least decimal places. Example: 12.11 3.2 = 15.31 → round to 15.3 ⭐ Rounding Rules (Very Important) If the digit to be removed is 5 → leave previous digit unchanged. If it is 5 → increase previous digit by 1. If it is exactly 5 → If previous digit is even, leave it (even rule). If previous digit is odd, add +1.