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9324e50d-f65e-4955-8e80-b8e942430055 Products Summary The substances that are formed during a chemical reaction.

3d51ee66-6dbf-4730-90eb-260b9e9ffd8b Subscript Summary The number used after a chemical symbol to indicate the number of atoms present per molecule

268eabeb-228c-42b2-baca-189b760eb22b Physical Change Summary Produces no new kind of matter, is generally easily reversible, is not accompanied by great heat change, produces no observable change in mass

Chapter 9 SABIS Grade 10 ● Chapter 9 Topics Heat Content (H): The amount of potential energy stored in 1 mole of any substance. Enthalpy Change (ΔH): Measures the difference between the heat content of the products and that of the reactants. Exothermic Reaction: A reaction in which the heat content of the products is less than the heat content of the reactants, energy is released. Endothermic Reaction: A reaction in which the heat content of the products is more than the heat content of the reactants, energy is absorbed. Bond Energy: The amount of energy needed to break a bond (usually measured in kJ/mole). Calorimetry: The measurement of the heats of reactions. A calorimeter is the device used to measure the heat of a reaction. Hess’s Law: The heat evolved or absorbed by a reaction is independent of the path followed and depends only on the initial reactants and final products and their states. Electrical Work: The energy supplied by an electric current. Electric energy, W = I×V×t. Kinetic Energy: The energy due to motion, expressed as ½ mv². Potential Energy: The energy due to position, expressed as mgh. Properties of Subatomic Particles Involved in Nuclear Reactions: Understand the properties of subatomic particles involved in nuclear reactions. Conservation in Nuclear Reactions: In nuclear reactions, charge, number of protons, number of electrons, and number of neutrons are conserved. Fission Reaction: A nuclear reaction in which a heavy nucleus splits into two nuclei. Fusion Reaction: A nuclear reaction in which 2 nuclei combine to form a heavier, more stable nucleus. Mass of a Nucleus: The mass of a nucleus could be different from the sum of the masses of its nucleons. Energy Conversion: The difference in mass is transferred to energy according to the equation: E = mc².

42c6640c-1f62-4004-ae4c-509dd4ad470e Microscopic changes that take place when a liquid is warmed Summary When a liquid is warmed in thermochemistry, several microscopic changes occur at the molecular level. These changes involve the increased kinetic energy of the liquid molecules and their interactions, leading to observable macroscopic effects such as expansion and changes in physical properties. As the liquid is heated, the temperature of the system rises, and this increase in temperature corresponds to an increase in the average kinetic energy of the liquid molecules. The molecules gain energy and move more rapidly, exhibiting increased vibrational, rotational, and translational motion. The increased kinetic energy causes the intermolecular forces between the liquid molecules to weaken. In the liquid state, these forces, such as hydrogen bonding or London dispersion forces, hold the molecules together in a cohesive arrangement. As the molecules gain energy, the forces become less effective at maintaining this cohesion. The weakened intermolecular forces result in an expansion of the liquid. The increased molecular motion and reduced intermolecular forces allow the molecules to move farther apart, leading to an increase in volume. This expansion is commonly observed in liquids when they are heated. Additionally, the increased kinetic energy can lead to changes in the physical properties of the liquid. For example, the viscosity of the liquid may decrease as the molecules move more freely and with less resistance. The surface tension may also decrease as the cohesive forces weaken, affecting the behavior of the liquid at interfaces. Furthermore, in some cases, when a liquid is heated sufficiently, it may undergo a phase change and transform into a gas. This transition occurs at the boiling point, where the vapor pressure of the liquid becomes equal to the external pressure. The heated liquid absorbs energy to overcome intermolecular forces and transition into a gas phase. It's important to note that the microscopic changes in a liquid being warmed are reversible. When the liquid is cooled, the molecules lose kinetic energy, and the intermolecular forces regain their effectiveness, leading to a decrease in volume and a return to the initial state. Understanding the microscopic changes that occur when a liquid is warmed is crucial in thermochemistry and various applications. It allows us to analyze energy transfers, phase transitions, and the behavior of substances under different temperature conditions. In summary, when a liquid is warmed in thermochemistry, microscopic changes take place at the molecular level. The increased kinetic energy of the molecules weakens the intermolecular forces, resulting in expansion, changes in physical properties, and, in some cases, phase transitions. Recognizing and studying these microscopic changes enhances our understanding of energy transfer and the behavior of liquids at different temperatures.

< Back Unit 1 AP Chemistry Topic 1 Molar Mass This is Unit 1 AP Chemistry The Mole Concept You can get more out of your site elements by making them dynamic. To connect this element to content from your collection, select the element and click Connect to Data. Once connected, you can save time by updating your content straight from your collection—no need to open the Editor, or mess with your design. Add any type of content to your collection, such as rich text, images, videos and more, or upload a CSV file. You can also collect and store information from your site visitors using input elements like custom forms and fields. Collaborate on your content across teams by assigning permissions setting custom permissions for every collection. Be sure to click Sync after making changes in a collection, so visitors can see your newest content on your live site. Preview your site to check that all your elements are displaying content from the right collection fields. Ready to publish? Simply click Publish in the top right of the Editor and your changes will appear live. Unit 1 Topic 1 Moles and Molar Mass The Molar Mass Previous Next

23d5d3ae-6e0d-4b55-8d00-5678732e4bd3 Endothermic Reaction Summary Is a reaction which absorbs heat from the surrounding. As heat is absorbed, the temperature of the surrounding decreases. Decomposition reactions like electrolysis of water, heating a substance, melting, vaporization and sublimation are examples of endothermic processes

bd4da886-2334-42b4-924e-b7b87c2bde87 Electrical Work Summary Electric work is the energy supplied by an electric current. In thermochemistry, it refers to the energy transfer that occurs during an electrochemical reaction or when electrical energy is used to perform work. To understand electric work, let's consider an everyday example: charging a mobile phone. When you connect your phone to a charger, electrical energy flows from the power source to the phone's battery. This energy transfer allows the battery to store electrical energy, which can later be used to power the phone and perform various tasks. Similarly, when you plug in an electrical device such as a laptop or a blender, electric work is done to power the device and enable its functionality. The electrical energy supplied through the power cord allows the device to operate and perform the desired tasks. In thermochemistry, electric work is involved in various electrochemical processes. For instance, during electrolysis, an electric current is passed through a solution or molten compound, causing a chemical reaction to occur. This reaction is driven by the electric work performed, leading to the separation or deposition of substances. Consider the process of electroplating, where a thin layer of metal is deposited onto an object. By passing an electric current through a solution containing metal ions, the metal ions are reduced and form a solid metal layer on the object's surface. The electrical work is responsible for driving this electrochemical process. Electric work is also crucial in battery technology. When a battery is used to power a device, such as a flashlight or a remote control, electric work is done as the chemical reactions inside the battery generate an electric current. This current supplies the necessary energy for the device to function. In summary, electric work in thermochemistry refers to the energy transfer that occurs during electrochemical reactions or when electrical energy is used to perform work. Examples include charging a mobile phone, operating electrical devices, electrolysis, electroplating, and battery-powered devices. Understanding electric work helps explain the energy transformations involved in various electrochemical processes and the role of electrical energy in powering everyday devices.

d9f0746a-a349-4d0b-9449-06356cabc734 In the periodic table, metals are found to the left whereas non-metals are found to the right. Summary

Get ready to ace your IGCSE Chemistry exams with our Final Revision Course for May 2023! Our comprehensive course covers all the essential topics, from chemical reactions and bonding to organic chemistry and fuels. With engaging video lessons, detailed study guides, and expert tuition, you'll be fully prepared to tackle any question that comes your way. Don't let your IGCSE Chemistry exams catch you off guard – sign up for our Final Revision Course today and take your studies to the next level! Final Revision IGCSE 0620 Chemistry Winter OCT NOV 2023 Day 1 Day 1Material Read More Day 2 Day 2Material Read More Day 3 Day 3 Material Read More Day 4 Day 4 Material Read More Day 5 Day 5 Material Isomers Read More Day 6 Day 6 Material Alcohols esters and carboxylic acids review Read More Day 7 Day 7 Material Thermochemistry Read More Day 8 Day 8 Material Acids Bases and Salts Read More Day 9 Day 9 Revise Experimental Techniques Read More Day 10 Day 10 Material Petroleum and Fossil Fuels Read More Day 11 Day 11 Material Fast Organic chemistry Review Read More Day 12 Day 12 Material Electrochemistry Read More Day 13 Day 13 Material Acids Bases and Salts Read More Day 14 Day 14 Material Metals Read More Day 15 Day 15 Atoms Elements and Compounds Read More Day 16 Day 16 Addition Polymers Read More Day 17 Day 17 Stoichiometry Fast Revision Read More Day 18 Day 18 Condensation Polymerisation Read More Day 19 Day 19 Definitions Read More Day 20 Day 20 States of Matter Read More Day 21 Day 21 States of Matter part 2 Read More Day 22 Day 22 Extraction of Iron Read More Day 23 Day 23 Experimental Techniques Read More Day 24 Day 24 paper 6 Final Revision Read More Day 30 Day 30 Final Revision Read More

Lesson 41 More Families of Elements & Periodic Trends Chapter 7 SABIS Grade 10 Part 3 Lesson 41 More Families of Elements & Periodic Trends Points explained Meaning of the word “stable” Reactions of the alkali metals with chlorine Reactions of the alkali metals with water Reactions of the alkali metals with hydrogen Flame test for Li+ , Na+ and K+ Summary of chemistry of the alkali metals 7.6 The Halogens 7.6.1 Physical properties of the halogens 7.6.2 Covalent bonding in the halogens Defining a covalent bond Differences between covalent and ionic bonding 7.6.3 Boiling points and melting points of the halogens 7.6.4 Atomic radii and volumes 7.6.5 Chemistry of the halogens Reactions with the alkali metals Summary 7.6.6 Chemistry of the halide ions The halides are stable Test for the halide ions Relative reactivity of the halogens 7.7 Hydrogen - A Family by Itself 7.7.1 Physical properties 7.7.2 Chemistry of hydrogen Reaction with the alkali metals 7.8 The Third-row Elements 7.8.1 Physical properties of the third-row elements 7.8.2 Compounds of the third-row elements The hydrides The chlorides The oxides Summary 7.9 The periodic table: chemical reactivity 🔬Understanding Stability, Alkali Metals & Halogens 📚Pre-Requisite Questions: What does it mean for an element to be "stable"? 🤔 What happens when alkali metals react with chlorine? 🧪 Can you describe the flame test results for Li+, Na+, and K+? 🔥 Break for Reflection 🤔✍️ (Answers: 1. A stable element has a full outer electron shell and doesn't tend to react. 2. When alkali metals react with chlorine, they form ionic salts. 3. Li+ burns with a crimson flame, Na+ with a yellow flame, and K+ with a lilac flame.) 🚀 Lesson Begins! 🧱 Meaning of the Word “Stable” In the chemistry world, "stable" doesn't mean standing still! It means an atom has a full outer shell of electrons and is not looking to react. They're like that chill friend who's content with what they have! 😌 💥Reactions of the Alkali Metals 💦With Water Splash alert! Alkali metals react violently with water, producing heat, hydrogen gas, and an alkali metal hydroxide. Think of it as a bath bomb that's too explosive for the tub! 🛀💣 🎈With Hydrogen Pairing up! Alkali metals can combine with hydrogen to form metal hydrides, releasing energy in the process. It's like an energetic dance duo! 💃🕺 🔥Flame Test for Li+, Na+, and K+ Ready for some fireworks? 🎆 In the flame test, Li+ produces a red/crimson flame, Na+ gives a yellow flame, and K+ presents a lilac flame. It's like a mini festival of lights in the lab! 🎇 7.6 The Halogens The Halogens, just like the Alkali Metals, are an interesting bunch. They're like the goths of the periodic table, always looking to gain an electron to achieve stability. 🕶️💀 🧪Covalent Bonding in the Halogens Halogens form covalent bonds by sharing electrons. Imagine sharing your favorite pizza with a friend—that's how halogens share electrons to become stable. 🍕❤️ 🔥Boiling Points and Melting Points of the Halogens Halogens have higher boiling and melting points as we move down the group, thanks to the increasing number of electrons which cause stronger intermolecular forces. It's like adding more logs to the fire—the more you have, the higher the flame! 🏕️🔥 ⚖️Atomic Radii and Volumes Atomic radii also increase as we go down the group. It's kind of like siblings—the older ones tend to be bigger! 🧑🤝🧑 🔥Chemistry of the Halogens Halogens are pretty reactive. Their reactions with alkali metals form ionic salts, and they're not shy about displacing less reactive halogens. It's like a game of musical chairs! 🎶🪑 7.7 Hydrogen - A Family by Itself Hydrogen is unique. Despite being the lightest and simplest element, its properties don't quite fit into any group. So, it charts its own path—just like a lone wolf. 🐺⛰️ 7.8 The Third-row Elements The third-row elements are like the middle kids of the periodic table. They have their quirks and surprises! So, let's dive deeper into their physical properties and compounds. 🏊♂️🌊 7.9 The Periodic Table: Chemical Reactivity The periodic table is not just a chart; it's a tale of reactivity, trends, and atomic friendships. Keep exploring, keep learning! 🚀 Review Questions: What is meant by a stable element? a. It has a full outer electron shell b. It has no protons c. It is radioactive d. None of the above What happens when alkali metals react with water? a. Nothing b. They dissolve c. They produce heat and hydrogen gas d. They turn into halogens Which element doesn't fit well into any group in the periodic table? a. Hydrogen b. Helium c. Oxygen d. Nitrogen Which of the following is NOT a property of the halogens? a. They form ionic bonds b. They form covalent bonds c. They have high boiling and melting points d. They are very reactive (Answers: 1. a, 2. c, 3. a, 4. a) End of Lesson 3 ⭐Keep studying, keep learning!⭐