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Chemistry Energy Changes Or Chemical Energetics

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Quiz:   Fullscreen Mode Quiz 2: Fullscreen Mode Chemistry Energy Changes Or Chemical Energetics 🌡️ CHEMISTRY: ENERGY CHANGES 1. Exothermic & Endothermic Reactions Exothermic: Reaction that releases heat to surroundings → Temperature RISES → ΔH is NEGATIVE (ΔH Endothermic: Reaction that absorbs heat from surroundings → Temperature FALLS → ΔH is POSITIVE (ΔH > 0) Type Heat Flow Temperature ΔH Sign Examples Exothermic OUT ↗ RISES ↑ NEGATIVE (−) Combustion, respiration, neutralization Endothermic IN ↘ FALLS ↓ POSITIVE (+) Photosynthesis, thermal decomposition 2. Enthalpy Change (ΔH) Enthalpy Change (ΔH): Transfer of thermal energy during a reaction, measured in kilojoules (kJ) Main Formula: ΔH = Total energy of products − Total energy of reactants Example 1 (Exothermic): Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s) ΔH = −150 kJ (negative = heat released) Example 2 (...
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Electrical Circuits and Electrical Safety

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Other note source Quiz 1:   Fullscreen Mode Quiz 2: Fullscreen Mode Electrical Circuits and Electrical Safety A Complete Guide for Grade 7 Students 17.1 Circuit Diagrams and Components Circuit diagrams use symbols to represent electrical components. This makes it easier to design and understand circuits. Symbol Name Function Cell Single battery (1.5V). Long line = positive (+), short line = negative (-) ...
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Continuous random variables

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Other Source Ringkasan Teori & Rumus Variabel Acak Kontinu 1. Definisi Variabel Acak Kontinu Variabel acak kontinu X dapat memiliki nilai apa pun dalam interval kontinu . Contoh: tinggi badan, waktu tunggu, suhu, laju peluruhan radioaktif. 2. Fungsi Kepadatan Peluang (PDF) Syarat PDF f(x) : 1. f(x) ≥ 0 untuk semua x 2. ∫ -∞ ∞ f(x) dx = 1 (total luas = 1) Grafik PDF f(x) x 3. Menghitung Peluang Karena P(X = a) = 0 , peluang hanya bisa dihitung untuk interval: P(a ≤ X ≤ b) = ∫ a b f(x) dx Untuk grafik sederhana bisa juga dengan geometri (luas segiempat, trapesium, segitiga). 4. Nilai Tengah (Median) Median m adalah nilai yang memenuhi: ∫ -∞ m f(x) dx = 0.5 Intuisi: letak vertikal yang membelah luas kurva menjadi dua bagian sama besar. 5. Persentil Umum Persentil- p (0 < p < 1) adalah q sedemikian hingga: ∫ -∞ q f(x) dx = p 6. Nilai Harapan (Mean) E(X) = μ = ∫ -∞ ∞ x f(x) dx 7. Varia...
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Lines, Angles and Shapes

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Quiz 1: Fullscreen Mode Other Quiz Lines, Angles and Shapes - Theory and Formulas 3.1 Lines and Angles Types of Angles Angles can be classified based on their size: Type Size Example Acute angle Less than 90° 30°, 45°, 70° Right angle Exactly 90° Corner of a book Obtuse angle More than 90° but less than 180° 100°, 120°, 150° Reflex angle More than 180° but less than 360° 200°, 270°, 300° Special Pairs of Angles Complementary Angles: Two angles that add up to 90° . Supplementary Angles: Two angles that add up to 180° . Fundamental Angle Rules Angles on a Straight Line: The sum of angles on a straight line is 180° . ∑ ∠ on line = 180° Angles Around a Point: The sum of all angles around a single point is 360° . ∑ ...
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Logarithmic And Exponential Functions

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Logarithmic & Exponential Functions All-in-One Theory Sheet 2.1 Logarithms to Base 10 Definition: If 10 x = y , then log 10 y = x (written log y for short). ┌-----┐ │ 10 │ │ ^ │ ← Exponent │ y │ └-----┘ log 1000 = 3 because 10³ = 1000 log 0.01 = –2 because 10 –2 = 0.01 2.2 Logarithms to Any Base a Definition: If a x = y with a > 0 and a ≠ 1 , then log a y = x . log₂ 32 = 5 because 2⁵ = 32 log₅ 1 = 0 because 5⁰ = 1 2.3 The Three Laws of Logarithms ┌-------┐ │ Laws │ └-------┘ Product: log a (xy) = log a x + log a y Quotient: log a (x / y) = log a x – log a y Power: log a (x n ) = n log a x 2.4 Solving Logarithmic Equations Golden Rule: Logs only exist for positive numbers. Use the laws to get a single log on each side. Drop the log...
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