{
  "title": "Standard Form (Scientific Notation) - Grade 9 ICSE",
  "total_questions": 60,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "What is 5,400 in standard form? 🧐", "options": {"A": "5.4 × 10²", "B": "5.4 × 10³", "C": "54 × 10²", "D": "0.54 × 10⁴"}, "correct_answer": "B"},
    {"id": 2, "difficulty": "easy", "question": "Express 0.0072 in standard form. 📝", "options": {"A": "7.2 × 10⁻³", "B": "7.2 × 10³", "C": "72 × 10⁻⁴", "D": "0.72 × 10⁻²"}, "correct_answer": "A"},
    {"id": 3, "difficulty": "easy", "question": "What is 1 × 10⁵ in ordinary form? 🔢", "options": {"A": "10000", "B": "100000", "C": "1000", "D": "10"}, "correct_answer": "B"},
    {"id": 4, "difficulty": "easy", "question": "Write 6.3 × 10⁴ as a normal number. ✍️", "options": {"A": "630", "B": "6300", "C": "63000", "D": "630000"}, "correct_answer": "C"},
    {"id": 5, "difficulty": "easy", "question": "Express 0.00089 in scientific notation. 🔬", "options": {"A": "8.9 × 10⁻⁴", "B": "89 × 10⁻⁵", "C": "8.9 × 10⁴", "D": "0.89 × 10⁻³"}, "correct_answer": "A"},
    {"id": 6, "difficulty": "easy", "question": "What is the standard form of 12,300? 🏙️", "options": {"A": "1.23 × 10⁴", "B": "12.3 × 10³", "C": "123 × 10²", "D": "0.123 × 10⁵"}, "correct_answer": "A"},
    {"id": 7, "difficulty": "easy", "question": "Convert 8 × 10⁻³ to decimal form. ⚙️", "options": {"A": "0.8", "B": "0.08", "C": "0.008", "D": "0.0008"}, "correct_answer": "C"},
    {"id": 8, "difficulty": "easy", "question": "Write 4,500,000 in standard form. 🌍", "options": {"A": "4.5 × 10⁵", "B": "4.5 × 10⁶", "C": "45 × 10⁵", "D": "0.45 × 10⁷"}, "correct_answer": "B"},
    {"id": 9, "difficulty": "easy", "question": "What is 0.0506 in scientific notation? 🧪", "options": {"A": "5.06 × 10⁻²", "B": "50.6 × 10⁻³", "C": "5.06 × 10²", "D": "0.506 × 10⁻¹"}, "correct_answer": "A"},
    {"id": 10, "difficulty": "easy", "question": "Express 9 × 10² as an ordinary number. 🎯", "options": {"A": "90", "B": "900", "C": "9000", "D": "9"}, "correct_answer": "B"},
    {"id": 11, "difficulty": "easy", "question": "The standard form of 0.000043 is? 🔍", "options": {"A": "4.3 × 10⁻⁵", "B": "43 × 10⁻⁶", "C": "4.3 × 10⁵", "D": "0.43 × 10⁻⁴"}, "correct_answer": "A"},
    {"id": 12, "difficulty": "easy", "question": "What is 7.21 × 10³ in normal form? 📍", "options": {"A": "721", "B": "7210", "C": "72.1", "D": "0.721"}, "correct_answer": "B"},
    {"id": 13, "difficulty": "easy", "question": "Write 602,000 in standard form. 💡", "options": {"A": "6.02 × 10⁵", "B": "60.2 × 10⁴", "C": "602 × 10³", "D": "6.02 × 10⁶"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "Convert 3.08 × 10⁻² to decimal. 📐", "options": {"A": "0.308", "B": "0.0308", "C": "0.00308", "D": "3.08"}, "correct_answer": "B"},
    {"id": 15, "difficulty": "easy", "question": "Express 100,000 as a power of 10. ⚡", "options": {"A": "10⁴", "B": "10⁵", "C": "10⁶", "D": "1 × 10⁵"}, "correct_answer": "B"},
    {"id": 16, "difficulty": "easy", "question": "What is 0.001 × 10² in standard form? 🌀", "options": {"A": "1 × 10⁻¹", "B": "1 × 10¹", "C": "1 × 10⁰", "D": "1 × 10⁻⁴"}, "correct_answer": "A"},
    {"id": 17, "difficulty": "easy", "question": "Write 2.5 × 10⁰ as a number. 😄", "options": {"A": "25", "B": "2.5", "C": "0.25", "D": "250"}, "correct_answer": "B"},
    {"id": 18, "difficulty": "easy", "question": "The scientific notation for 80,000 is? 🚀", "options": {"A": "8 × 10³", "B": "8 × 10⁴", "C": "80 × 10³", "D": "0.8 × 10⁵"}, "correct_answer": "B"},
    {"id": 19, "difficulty": "easy", "question": "Convert 6.7 × 10¹ to ordinary form. 🛠️", "options": {"A": "67", "B": "670", "C": "6.7", "D": "0.67"}, "correct_answer": "A"},
    {"id": 20, "difficulty": "easy", "question": "What is 0.09 × 10⁻² in standard form? ✨", "options": {"A": "9 × 10⁻⁴", "B": "9 × 10⁻³", "C": "9 × 10⁻²", "D": "9 × 10⁻¹"}, "correct_answer": "A"},
    {"id": 21, "difficulty": "medium", "question": "Calculate: (3 × 10⁴) × (2 × 10²). ⚡", "options": {"A": "6 × 10⁶", "B": "6 × 10⁸", "C": "5 × 10⁶", "D": "6 × 10²"}, "correct_answer": "A"},
    {"id": 22, "difficulty": "medium", "question": "Divide: (8 × 10⁸) ÷ (2 × 10³). ➗", "options": {"A": "4 × 10⁵", "B": "4 × 10¹¹", "C": "6 × 10⁵", "D": "4 × 10⁴"}, "correct_answer": "A"},
    {"id": 23, "difficulty": "medium", "question": "Add: 5.2 × 10³ + 3.8 × 10³. ➕", "options": {"A": "9.0 × 10³", "B": "9.0 × 10⁶", "C": "8.0 × 10³", "D": "9.0 × 10²"}, "correct_answer": "A"},
    {"id": 24, "difficulty": "medium", "question": "Subtract: 7.5 × 10⁴ - 2.5 × 10⁴. ➖", "options": {"A": "5.0 × 10⁰", "B": "5.0 × 10⁴", "C": "5.0 × 10⁸", "D": "10.0 × 10⁴"}, "correct_answer": "B"},
    {"id": 25, "difficulty": "medium", "question": "Find: (4 × 10⁻³) × (5 × 10²). ✖️", "options": {"A": "20 × 10⁻¹", "B": "2.0 × 10⁰", "C": "2.0 × 10⁻⁵", "D": "9 × 10⁻¹"}, "correct_answer": "B"},
    {"id": 26, "difficulty": "medium", "question": "Simplify: (6 × 10⁵) ÷ (3 × 10⁻²). 🧮", "options": {"A": "2 × 10⁷", "B": "2 × 10³", "C": "18 × 10³", "D": "2 × 10⁻⁷"}, "correct_answer": "A"},
    {"id": 27, "difficulty": "medium", "question": "What is (2.1 × 10⁶) + (3.9 × 10⁶)? 🧱", "options": {"A": "6.0 × 10⁶", "B": "6.0 × 10¹²", "C": "5.0 × 10⁶", "D": "6.0 × 10⁵"}, "correct_answer": "A"},
    {"id": 28, "difficulty": "medium", "question": "Calculate: (9 × 10⁸) / (4.5 × 10²). 📊", "options": {"A": "2 × 10⁶", "B": "2 × 10⁴", "C": "4.5 × 10⁶", "D": "2 × 10¹⁰"}, "correct_answer": "A"},
    {"id": 29, "difficulty": "medium", "question": "Express the product in standard form: (7 × 10⁻⁴)(2 × 10⁻³). 🔬", "options": {"A": "14 × 10⁻⁷", "B": "1.4 × 10⁻⁶", "C": "1.4 × 10⁻⁷", "D": "14 × 10⁻⁶"}, "correct_answer": "B"},
    {"id": 30, "difficulty": "medium", "question": "If a = 3 × 10² and b = 4 × 10³, find a × b. 🤝", "options": {"A": "12 × 10⁵", "B": "1.2 × 10⁶", "C": "7 × 10⁵", "D": "12 × 10⁶"}, "correct_answer": "B"},
    {"id": 31, "difficulty": "medium", "question": "Light travels 3 × 10⁸ m/s. How far in 5 × 10² seconds? 🌠", "options": {"A": "15 × 10¹⁰ m", "B": "1.5 × 10¹¹ m", "C": "8 × 10¹⁰ m", "D": "1.5 × 10¹⁰ m"}, "correct_answer": "B"},
    {"id": 32, "difficulty": "medium", "question": "Simplify: (5.6 × 10⁷) - (2.1 × 10⁷). ✂️", "options": {"A": "3.5 × 10⁷", "B": "3.5 × 10⁰", "C": "3.5 × 10¹⁴", "D": "7.7 × 10⁷"}, "correct_answer": "A"},
    {"id": 33, "difficulty": "medium", "question": "Find: (8.4 × 10⁹) ÷ (4.2 × 10⁴). 📈", "options": {"A": "2 × 10⁵", "B": "2 × 10¹³", "C": "4.2 × 10⁵", "D": "2 × 10⁻⁵"}, "correct_answer": "A"},
    {"id": 34, "difficulty": "medium", "question": "Add: 4.3 × 10⁵ + 5.7 × 10⁵. 🎈", "options": {"A": "1.0 × 10⁶", "B": "1.0 × 10¹¹", "C": "10.0 × 10⁵", "D": "1.0 × 10⁵"}, "correct_answer": "A"},
    {"id": 35, "difficulty": "medium", "question": "A microsecond is 1 × 10⁻⁶ s. How many microseconds in 2 seconds? ⏱️", "options": {"A": "2 × 10⁶", "B": "2 × 10⁻⁶", "C": "0.5 × 10⁶", "D": "5 × 10⁵"}, "correct_answer": "A"},
    {"id": 36, "difficulty": "medium", "question": "Calculate: (1.2 × 10⁻³) × (3 × 10⁴). 🌿", "options": {"A": "3.6 × 10¹", "B": "3.6 × 10⁻⁷", "C": "3.6 × 10⁷", "D": "36 × 10¹"}, "correct_answer": "A"},
    {"id": 37, "difficulty": "medium", "question": "Subtract: 9.1 × 10⁴ - 4.1 × 10⁴. 🏁", "options": {"A": "5.0 × 10⁴", "B": "5.0 × 10⁸", "C": "13.2 × 10⁴", "D": "5.0 × 10⁰"}, "correct_answer": "A"},
    {"id": 38, "difficulty": "medium", "question": "Divide: (1.44 × 10¹²) ÷ (1.2 × 10⁴). 🧊", "options": {"A": "1.2 × 10⁸", "B": "1.2 × 10¹⁶", "C": "1.2 × 10⁻⁸", "D": "12 × 10⁸"}, "correct_answer": "A"},
    {"id": 39, "difficulty": "medium", "question": "Find the sum: 2.5 × 10³ + 7.5 × 10². 🤔", "options": {"A": "3.25 × 10³", "B": "10.0 × 10⁵", "C": "1.0 × 10⁴", "D": "3.25 × 10²"}, "correct_answer": "A"},
    {"id": 40, "difficulty": "medium", "question": "If Earth's mass is 6 × 10²⁴ kg and Moon's is 7.3 × 10²² kg, find their total mass. 🌍🌕", "options": {"A": "6.073 × 10²⁴ kg", "B": "13.3 × 10²⁴ kg", "C": "6.73 × 10²⁴ kg", "D": "1.33 × 10²⁵ kg"}, "correct_answer": "A"},
    {"id": 41, "difficulty": "hard", "question": "Simplify: [(4 × 10⁵)³ ÷ (8 × 10¹²)] × 10⁻³. 🏆", "options": {"A": "8 × 10⁻¹", "B": "8 × 10⁰", "C": "2 × 10⁰", "D": "2 × 10⁵"}, "correct_answer": "A"},
    {"id": 42, "difficulty": "hard", "question": "Calculate: (5.6 × 10⁻⁸)(2.5 × 10¹²) ÷ (4 × 10³). 🧮", "options": {"A": "3.5 × 10¹", "B": "3.5 × 10²", "C": "3.5 × 10⁰", "D": "3.5 × 10⁻¹⁹"}, "correct_answer": "A"},
    {"id": 43, "difficulty": "hard", "question": "Find x if (3 × 10ˣ)(4 × 10⁴) = 1.2 × 10¹⁰. 🔎", "options": {"A": "5", "B": "6", "C": "4", "D": "3"}, "correct_answer": "A"},
    {"id": 44, "difficulty": "hard", "question": "Evaluate: √(1.6 × 10⁻⁵) × √(4.0 × 10⁹). ⚡", "options": {"A": "8.0 × 10²", "B": "8.0 × 10¹", "C": "6.4 × 10⁴", "D": "6.4 × 10²"}, "correct_answer": "A"},
    {"id": 45, "difficulty": "hard", "question": "A star is 4.2 × 10¹³ km away. Light travels 9.46 × 10¹² km/year. Find travel time in years. 🌟", "options": {"A": "≈ 4.44 years", "B": "≈ 0.44 years", "C": "≈ 44.4 years", "D": "≈ 444 years"}, "correct_answer": "A"},
    {"id": 46, "difficulty": "hard", "question": "Simplify: [ (2.7 × 10⁶) - (1.2 × 10⁶) ] ÷ (5 × 10⁻²). 📉", "options": {"A": "3.0 × 10⁷", "B": "3.0 × 10⁸", "C": "1.5 × 10⁸", "D": "3.0 × 10⁴"}, "correct_answer": "A"},
    {"id": 47, "difficulty": "hard", "question": "If a = 2.5 × 10⁻⁴, b = 8 × 10⁻⁶, find a/b in standard form. ➗", "options": {"A": "3.125 × 10¹", "B": "3.125 × 10²", "C": "3.125 × 10⁻²", "D": "3.125 × 10⁻¹"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "hard", "question": "Solve: (x × 10⁵) + (2.4 × 10⁶) = 5.0 × 10⁶. Find x. ⚖️", "options": {"A": "2.6 × 10¹", "B": "2.6 × 10⁶", "C": "2.6 × 10⁰", "D": "2.6 × 10⁻¹"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "hard", "question": "Evaluate: (1.2 × 10³)² ÷ (4.8 × 10⁵). 🌀", "options": {"A": "3.0 × 10⁰", "B": "3.0 × 10⁻¹", "C": "3.0 × 10¹", "D": "3.0 × 10²"}, "correct_answer": "A"},
    {"id": 50, "difficulty": "hard", "question": "Add and express in standard form: 5.6 × 10⁻³ + 3.4 × 10⁻². ➕", "options": {"A": "3.96 × 10⁻²", "B": "9.0 × 10⁻²", "C": "3.96 × 10⁻³", "D": "4.0 × 10⁻⁵"}, "correct_answer": "A"},
    {"id": 51, "difficulty": "hard", "question": "A proton mass is 1.67 × 10⁻²⁷ kg. How many protons in 1 kg? ⚛️", "options": {"A": "≈ 5.99 × 10²⁶", "B": "≈ 1.67 × 10²⁷", "C": "≈ 6.0 × 10²³", "D": "≈ 1.67 × 10⁻²⁷"}, "correct_answer": "A"},
    {"id": 52, "difficulty": "hard", "question": "Simplify: (8.1 × 10¹¹) × (4.0 × 10⁻⁶) ÷ (3.6 × 10⁴). 🧬", "options": {"A": "9.0 × 10¹", "B": "9.0 × 10⁰", "C": "9.0 × 10²", "D": "9.0 × 10⁻¹"}, "correct_answer": "A"},
    {"id": 53, "difficulty": "hard", "question": "If (5 × 10ᵐ)ⁿ = 1.25 × 10¹⁵ and m=2, find n. 🎯", "options": {"A": "3", "B": "4", "C": "5", "D": "6"}, "correct_answer": "A"},
    {"id": 54, "difficulty": "hard", "question": "Find the difference: 7.08 × 10⁵ - 9.2 × 10⁴. ✂️", "options": {"A": "6.16 × 10⁵", "B": "6.16 × 10⁴", "C": "7.988 × 10⁵", "D": "-2.12 × 10⁵"}, "correct_answer": "A"},
    {"id": 55, "difficulty": "hard", "question": "The volume of a cube is 2.7 × 10⁻⁶ m³. Find its side length in standard form. ⬜", "options": {"A": "1.4 × 10⁻² m", "B": "3.0 × 10⁻² m", "C": "1.4 × 10⁻³ m", "D": "3.0 × 10⁻³ m"}, "correct_answer": "A"},
    {"id": 56, "difficulty": "hard", "question": "Evaluate: √(6.4 × 10⁻³) × (2.0 × 10²). 🌳", "options": {"A": "1.6 × 10⁰", "B": "1.6 × 10¹", "C": "3.2 × 10¹", "D": "1.28 × 10⁰"}, "correct_answer": "A"},
    {"id": 57, "difficulty": "hard", "question": "Divide 1.44 × 10⁻⁸ by 3.6 × 10⁻¹². 🧭", "options": {"A": "4.0 × 10³", "B": "4.0 × 10⁴", "C": "4.0 × 10⁻⁴", "D": "4.0 × 10⁻²⁰"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "hard", "question": "If the speed of light is 3 × 10⁸ m/s, find time (seconds) to travel 9 × 10¹⁰ m. ⏳", "options": {"A": "3 × 10²", "B": "3 × 10⁻²", "C": "2.7 × 10¹⁹", "D": "3 × 10¹⁸"}, "correct_answer": "A"},
    {"id": 59, "difficulty": "hard", "question": "Simplify: [(9 × 10¹⁰) + (11 × 10¹⁰)] / (5 × 10⁵). 🏹", "options": {"A": "4.0 × 10⁵", "B": "4.0 × 10¹⁵", "C": "4.0 × 10⁶", "D": "2.0 × 10⁵"}, "correct_answer": "A"},
    {"id": 60, "difficulty": "hard", "question": "A bacteria population doubles every hour. If initial is 5 × 10³, find population after 5 hours in standard form. 🦠", "options": {"A": "1.6 × 10⁵", "B": "2.5 × 10⁴", "C": "1.6 × 10⁶", "D": "5 × 10⁸"}, "correct_answer": "A"}
  ]
}