Quiz 1:   Fullscreen Mode Exothermic and Endothermic Reactions Exothermic and Endothermic Reactions Chemical reactions can be classified into two main categories based on energy changes: exothermic reactions and endothermic reactions . Exothermic Reactions An exothermic reaction is one that releases energy in the form of heat to the surroundings. During this reaction, the temperature of the surroundings increases due to the energy released. A common example of an exothermic reaction is the combustion of fuels, such as methane (CH₄). The combustion reaction of methane can be written as follows: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l) + ΔH Here, ΔH has a negative value, indicating that energy is released during this process. The combustion of methane in oxygen produces carbon dioxide and water, releasing about 728 kJ/mol of energy. Characteristics of Exothermic Reactions: Energy Released: Energy in the form of heat is released to the surround...

Quiz 1:   Fullscreen Mode Besaran dan Pengukuran A. Besaran Besaran adalah segala sesuatu yang dapat diukur dan dinyatakan dengan angka serta memiliki satuan tertentu. 1. Besaran Pokok Besaran pokok adalah besaran yang menjadi dasar dari besaran yang lain. Terdapat 7 besaran pokok dalam Sistem Internasional (SI): No Besaran Simbol Besaran Satuan SI Simbol Satuan SI 1 Panjang l meter m 2 Massa m kilogram kg 3 Waktu t sekon s 4 Suhu T kelvin K 5 Kuat Arus I ampere A 6 Jumlah Zat n mol mol 7 Intensitas Cahaya I candela cd 2. Besaran Turunan Besaran turunan adalah besaran yang diperoleh dari besaran pokok yang diturunkan. Beberapa contoh besaran turunan: Besaran Penjabaran Satuan Luas panjang × lebar m² Volume panjang × lebar × tinggi m³ Massa Jenis massa / volume kg/m³ Kecep...

Quiz 1   Fullscreen Mode Discrete Random Variables and Probability Distribution Discrete Random Variables A discrete random variable is a variable whose values are countable or finite, and these values occur randomly. Examples include: The number of broken eggs in a carton. The number of sixes rolled when throwing four dice. Characteristics of Discrete Random Variables Values are integers (e.g., 0, 1, 2, etc.). Each value has a specific probability of occurring. For example, when flipping two coins, the number of heads that appear is a discrete random variable X , with possible values X ∈ {0, 1, 2} . Probability Distribution A probability distribution describes the likelihood of each value of a random variable. For discrete random variables, the probability distribution can be presented as a table, bar graph, or function. Example: Flippin...

Audio Podcast Quiz 1:   Fullscreen Mode Quiz 2:   Fullscreen Mode  5.2.1 Detection of radioactivity ## Radioactivity Detection Radioactivity is the process of releasing radiation from an unstable atomic nucleus. We are all exposed to radiation from various sources every day. Let's discuss some important things about radioactivity: ## Background Radiation Sources Background radiation comes from a variety of sources, both natural and artificial: - Cosmic rays from the sun - Radon gas in the air - Radon-containing granite rocks - Potassium-40 in food - Medical procedures that use radioisotopes - Nuclear power plants and the rest of the nuclear bomb tests ## Ionization Effect Radiation can cause ionization, which is the process of releasing electrons from atoms or molecules. This can be evidenced by: Electroscope Experiments: - When a fire or radium source is brought close to a charged electroscope, the charge is lost - Fire or radiation causes air molecules...

Quiz 1   Fullscreen Mode Further Differentiation Further Differentiation 1. Increasing and Decreasing Functions A function y = f(x) is: Increasing : If dy/dx > 0 throughout the interval. Decreasing : If dy/dx < 0 throughout the interval. 2. Stationary Points Stationary points , also known as turning points, occur when: dy/dx = 0 3. First Derivative Test for Maximum and Minimum Points At a maximum point: dy/dx = 0 The gradient is positive to the left and negative to the right of the point. At a minimum point: dy/dx = 0 The gradient is negative to the left and positive to the right of the point. 4. Second Derivative Test for Maximum and Minimum Points If dy/dx = 0 and d²y/dx² < 0 , the point is a maximum. If dy/dx = 0 and d²y/dx² > ...