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cm³ Grade 10 SABIS SABIS A unit of volume equal to one cubic centimeter, equivalent to 1 milliliter.

Know that in for exothermic reactions H products < H reactants, ∆ H< 0 and reaction releases energy Grade 10 SABIS ​ In chemical reactions, an exothermic reaction is one that releases energy to the surroundings. It is characterized by the fact that the enthalpy (H) of the products is less than the enthalpy of the reactants. This change in enthalpy (∆H) is negative, indicating that energy is released during the reaction. To understand exothermic reactions, let's consider an everyday example: the combustion of a candle. When you light a candle, the wax reacts with oxygen in the air, and an exothermic reaction occurs. The energy stored in the wax is released as heat and light, producing a flame. In an exothermic reaction, the potential energy of the products is lower than that of the reactants. This means that the reactants have a higher energy level compared to the products. As the reaction progresses, energy is released to the surroundings, resulting in a decrease in potential energy. On a potential energy diagram for an exothermic reaction, the reactants are represented at a higher energy level compared to the products. The curve starts at a higher point (representing the energy of the reactants) and gradually decreases (representing the decrease in potential energy) as the reaction proceeds towards the products. The difference in potential energy between the reactants and products is the amount of energy released to the surroundings. The negative value of ∆H indicates that the reaction releases energy. This energy can be in the form of heat, light, or any other form of energy. In the case of the candle combustion example, the released energy is in the form of heat and light from the burning flame. Exothermic reactions are crucial in various processes. For instance, the combustion of fuels, such as gasoline in car engines or natural gas in stoves, is exothermic. The energy released during combustion is harnessed to perform useful work, such as powering vehicles or heating homes. Another example is the process of respiration in living organisms. Through cellular respiration, energy is released from glucose and other molecules, providing the necessary energy for cellular functions and activities. Exothermic reactions also play a role in many natural phenomena, such as the formation of crystals, the release of energy during chemical reactions in the human body, and the generation of heat and light in firework explosions. In summary, exothermic reactions are characterized by the release of energy to the surroundings. The enthalpy of the products is less than that of the reactants, resulting in a negative change in enthalpy (∆H). On a potential energy diagram, the potential energy decreases from the reactants to the products, indicating the energy released during the reaction. Understanding exothermic reactions helps us comprehend processes that release energy, such as combustion, respiration, and various natural phenomena.

< Back Group 17 ​ ​ Previous Next 🔬 Chapter 11: Group 17 🔬 Halogens and Their Compounds 🧫: Halogens such as chlorine, bromine, and iodine exist as covalent diatomic molecules. They are oxidizing agents, with fluorine being the strongest and iodine the weakest. Chlorine reacts with cold hydroxide ions in a disproportionation reaction to produce commercial bleach. Chlorine has various industrial uses, including the manufacture of PVC and halogenated hydrocarbons used as solvents, refrigerants, and in aerosols. Chlorination of water with chlorine is important for the prevention of diseases.

< Back Nitrogen and sulfur ​ ​ Previous Next 🔬 Chapter 13: Nitrogen and Sulfur 🔬 Learning Outcomes 🎯: Describe and explain the lack of reactivity of nitrogen gas, the basicity of ammonia, and the formation and structure of the ammonium ion. State the industrial importance of ammonia and nitrogen compounds derived from ammonia. State and explain the environmental consequences of the uncontrolled use of nitrate fertilizers. Describe the natural and man-made occurrences of oxides of nitrogen and their catalytic removal from exhaust gases of internal combustion engines. Describe the formation of sulfur dioxide gas from sulfur-contaminated fossil fuel, its role in the formation of acid rain, and how acid rain affects the environment. Nitrogen and Its Compounds 🌬️: Nitrogen gas is relatively unreactive due to the triple bond between nitrogen atoms in N2 molecules. Ammonia is a basic compound that forms the ammonium ion when it reacts with acids. Ammonia and its derivatives are industrially important, especially in the production of fertilizers. Environmental Impact of Nitrogen Compounds 🌍: The excessive use of nitrate fertilizers can lead to environmental problems such as water pollution and eutrophication. Oxides of nitrogen are pollutants that can be produced naturally or by human activities, such as combustion in engines. They play a role in the formation of acid rain. Sulfur Dioxide and Acid Rain ☔: Sulfur dioxide is produced when sulfur-containing fossil fuels are burned. It is a major contributor to acid rain, which can have harmful effects on the environment, including soil, water, and buildings.

< Back A level Organic chemistry ​ ​ Previous Next

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< Back Alkanes Alkanes may seem difficult at first. The nomenclature, the structures, the reactions - it can all be overwhelming. But don't let that discourage you. Because every great organic chemist started where you are. They faced the same challenges and setbacks, but they never gave up. They never let the complexity defeat them. Files Download DAY 12 Notes Alkanes The IGCSE Organic Chemistry Challenge 2 .pdf Download PDF • 6.14MB Notes Topic Exercise Answers DAY 13 .14 HW part 1 and 2 Alkanes The IGCSE Organic Chemistry Challenge .pdf Download PDF • 14.40MB answers DAY 13 .14 HW part 1 and 2 Alkanes The IGCSE Organic Chemistry Challenge .pdf Download PDF • 17.28MB Videos Previous Next

< Back Atomic Structure Lesson 2 ⚛️ Lesson 2 ⚛️ This section delves into the mass and charge distributions within the atom, emphasizing the nucleus as the center of mass and the dance of electrostatic attraction that holds the atom together, while also highlighting the distinct movements of electrons, protons, and neutrons in an electric field. Previous Next ⚛️ 1.1.2 Mass, Charge & Subatomic Particles ⚛️ ✨🔬 Unmasking the Atom: Unveiling Mass & Charge Distributions 🔬✨ 1️⃣ The Mighty Nucleus: A Mass Reservoir 🏋️‍♀️🎯 Like a dense treasure chest in the heart of the atom, the nucleus is where the hefty subatomic heroes reside—the mighty protons and neutrons. They hoard nearly all of the atom's mass, with their combined weight making the nucleus the weightlifting champion of the atomic world. 🏆🌍 2️⃣ Electrons: The Lightweight Performers 💃⚡ Flirting around this massive nucleus, you'll find the feathery electrons. Their mass is so negligible, they're like tiny dancers pirouetting around a grand stage. Despite their lightness, they wear cloaks of negative charge, creating a bustling 'cloud' of negativity around the positive heart of the atom. ⛅💨 3️⃣ The Atom's Secret Glue: Electrostatic Attraction 🔗🧲 And what stops these nimble electrons from flitting away? The invisible ties of electrostatic attraction! The positive nucleus and negative electrons are drawn to each other, a captivating dance of opposite charges that keeps the atom together. 💖 ✨🎢 Subatomic Particles: Performers in an Electric Field 🎢✨ 1️⃣ The Electron's Graceful Waltz 🩰🌀 Imagine our subatomic performers, each moving at the same pace, but through a charged, electric stage. The electron, wearing its negative charge, is deflected away from the negative plate and is lured towards the positive plate with ease. This behavior not only proves its negative charge but also showcases its incredibly small mass as it pirouettes nimbly in the electric field. 🎭💫 2️⃣ The Proton's Powerful Stride 🏃‍♂️⚡ In contrast, the proton, with its positive charge, displays a different performance. It strides away from the positive plate and towards the negative one, asserting its positive nature. But compared to the electron's swift deflection, the proton's move is less pronounced, hinting at its greater mass. 💪🎖️ 3️⃣ The Neutron's Neutral Stand 🧍‍♂️🎭 What about the neutron? Well, the neutron, true to its neutral character, remains unaffected by the charged plates. It does not veer towards or shy away from either plate, simply continuing its journey unaffected—an applause-worthy performance proving its neutral nature. 👏🎭 So, there you have it—our subatomic performers illuminating the atom's inner workings through their mesmerizing dance in the atomic world and electric field! 🌠🌌 Quiz: Mass, Charge & Subatomic Particles ✨🔬 Unmasking the Atom: Unveiling Mass & Charge Distributions 🔬✨ Complete the missing words in the following questions: What resides in the nucleus and holds nearly all of the atom's mass? Answer: 🌟 Protons and neutrons Electrons have __________ mass compared to protons and neutrons. Answer: 🌌 Negligible/lightweight What creates an electric field that influences the movement of charged particles? Answer: 🔋 Charged plates Electrons are ____________ to the positive nucleus due to electrostatic attraction. Answer: 💞 Attracted In an electric field, electrons are deflected ____________ from the negative plate and toward the positive plate. Answer: 🌪 Away The proton, with its positive charge, moves ____________ from the positive plate and toward the negative plate in an electric field. Answer: 💥 Away Neutrons remain ____________ by the charged plates in an electric field due to their neutral nature. Answer: 🌟 Unaffected Protons have a ____________ mass compared to electrons. Answer: 💪 Greater The electron's movement in an electric field showcases its ____________ charge and small mass. Answer: 💫 Negative Neutrons demonstrate their ____________ nature by not veering towards or away from the charged plates in an electric field. Answer: 👏 Neutral Keep up the great work in understanding the mesmerizing dance of subatomic particles and their role in the atom's mass and charge distributions! 🎉🌠

The process of cooling liquid paradichlorobenzene until it solidifies Grade 10 SABIS SABIS Exothermic

Physical Change Grade 10 SABIS SABIS Produces no new kind of matter, is generally easily reversible, is not accompanied by great heat change, produces no observable change in mass

< Back Chemical Thermodynamics Prerequisites ​ Prerequisite Previous Next 🌟📘 Prerequisites for Chapter 6: Chemical Thermodynamics 📘🌟 Before diving into Chapter 6, which deals with chemical thermodynamics, students must have a solid understanding of the following concepts: 🔬 1. Basic Chemistry Concepts 🧪 Understand atoms, molecules, and chemical reactions. 🔬 2. Energy and Heat 🔥 Understand the concept of energy and the difference between heat and temperature. 🔬 3. Chemical Bonds 💪 Understand the energy involved in the formation and breaking of chemical bonds. 🔬 4. The Mole Concept 🐾 Understand the concept of moles and Avogadro's number. 🔬 5. Basic Mathematics 🧮 Be comfortable with algebra and solving equations. 🌟 20 Multiple Choice Questions to Check Mastery of Prerequisites 🌟 What is the smallest unit of an element that retains the properties of that element? a) Molecule b) Atom c) Electron d) Compound What is the energy called that is needed to break a chemical bond? a) Activation energy b) Bond energy c) Kinetic energy d) Potential energy How many atoms are in one mole of a substance? a) 6.022 x 10²³ b) 12 c) 1000 d) 1 What is the standard unit of temperature? a) Kelvin b) Celsius c) Fahrenheit d) Rankine What is the energy change of a system called? a) Enthalpy b) Entropy c) Heat d) Work What is the heat absorbed or released at constant pressure called? a) Internal energy b) Entropy c) Enthalpy d) Work What is the standard unit of energy? a) Joule b) Calorie c) Watt d) Newton What is the term for a reaction that absorbs heat from the surroundings? a) Exothermic b) Endothermic c) Isothermal d) Adiabatic What is the term for the average kinetic energy of particles in a substance? a) Heat b) Temperature c) Enthalpy d) Entropy Which law states that energy cannot be created or destroyed? a) First Law of Thermodynamics b) Second Law of Thermodynamics c) Hess's Law d) Law of Conservation of Mass What is the heat content of a system at constant pressure called? a) Internal energy b) Entropy c) Enthalpy d) Work What type of reaction releases heat to the surroundings? a) Exothermic b) Endothermic c) Isothermal d) Adiabatic What is the heat transfer into or out of a system called? a) Internal energy b) Entropy c) Enthalpy d) Heat What is the standard unit of pressure? a) Pascal b) Atmosphere c) Torr d) Bar What is the term for the heat transfer that occurs with no change in temperature? a) Latent heat b) Specific heat c) Enthalpy d) Entropy What is the term for the disorder or randomness of a system? a) Internal energy b) Entropy c) Enthalpy d) Heat In an exothermic reaction, the energy of the products is _______ than the energy of the reactants. a) Higher b) Lower c) The same d) Cannot be determined What is the heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius called? a) Latent heat b) Specific heat c) Enthalpy d) Entropy What is the term for a reaction where the reactants and products are in equilibrium with each other? a) Dynamic equilibrium b) Static equilibrium c) Chemical equilibrium d) Physical equilibrium What is the term for the minimum energy required for a chemical reaction to occur? a) Activation energy b) Bond energy c) Kinetic energy d) Potential energy 🌟 Answers 🌟 b) Atom b) Bond energy a) 6.022 x 10²³ a) Kelvin a) Enthalpy c) Enthalpy a) Joule b) Endothermic b) Temperature a) First Law of Thermodynamics c) Enthalpy a) Exothermic d) Heat a) Pascal a) Latent heat b) Entropy b) Lower b) Specific heat a) Dynamic equilibrium a) Activation energy

< Back Chemical Bonding prerequisite ​ Prerequisite Previous Next 🌟📘 Prerequisites for Chapter 4: Chemical Bonding 📘🌟 Before diving into Chapter 4, which deals with chemical bonding, students must have a solid understanding of the following concepts: 🔬 1. Atomic Structure 🧪 Understand the structure of an atom including protons, neutrons, and electrons. Know the arrangement of electrons in energy levels or shells. 🔬 2. Periodic Table 📊 Understand the arrangement of elements in the periodic table. Know the trends in atomic size, electronegativity, and ionization energy across periods and down groups. 🔬 3. Ion Formation ⚛️ Understand how ions are formed by the loss or gain of electrons. Know the difference between cations and anions. 🔬 4. Electronegativity ⚡ Understand the concept of electronegativity and its role in bond formation. 🔬 5. Valence Electrons 🎯 Know how to determine the number of valence electrons in an atom. Understand the role of valence electrons in bond formation. 🔬 6. Basic Stoichiometry 🧮 Understand the law of conservation of mass. Be able to balance chemical equations. 🔬 7. Types of Chemical Bonds 💥 Have a basic understanding of ionic and covalent bonds. 🌟 20 Questions to Check Mastery of Prerequisites 🌟 What are the three subatomic particles of an atom? 🤔 How many electrons can the first and second energy levels hold? 🔄 What is the charge of a proton? ➕ Define electronegativity. 🧲 Which element has the highest electronegativity? 🏆 How does atomic size change as you move across a period? 📉 What is the difference between a cation and an anion? ⚖️ How many valence electrons does oxygen have? 🎱 Write the electron configuration of carbon. ✍️ What is the octet rule? 🎱 What type of bond is formed when electrons are shared between atoms? 🤝 What type of bond is formed when electrons are transferred from one atom to another? 🔄 What is the chemical formula for sodium chloride? 🧂 Balance the following chemical equation: H2 + O2 -> H2O ⚖️ What is ionization energy? 💥 How many valence electrons are in an atom of chlorine? 🍀 What is the role of valence electrons in chemical bonding? 🤔 Define covalent bond. 🌉 Define ionic bond. ⚡ Which group of elements in the periodic table is known as the noble gases? 👑 🌟 Answers 🌟 Protons, neutrons, and electrons. First can hold 2, second can hold 8. +1. Electronegativity is the ability of an atom to attract electrons in a chemical bond. Fluorine. It decreases. Cations are positively charged, and anions are negatively charged. 1s² 2s² 2p². Atoms tend to gain, lose, or share electrons to have a full outer shell of 8 electrons. Covalent bond. Ionic bond. NaCl. 2H₂ + O₂ -> 2H₂O. Ionization energy is the energy required to remove an electron from an atom. Valence electrons are involved in forming chemical bonds with other atoms. A covalent bond is a chemical bond formed by the sharing of electron pairs between atoms. An ionic bond is a chemical bond formed by the transfer of electrons from one atom to another, resulting in the formation of positively and negatively charged ions. Group 18.