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Heating a mixture of hydrogen and oxygen until it “pops”, and then cooling the gases to a liquid Grade 10 SABIS SABIS Chemical

Endothermic Reaction Grade 10 SABIS SABIS 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

< Back Atomic Structure Lesson 7 ⚛️ Lesson 7 ⚛️ Section Test 1 , Test 2 Previous Next Quiz 1 : Atomic Structure, Isotopes, and Subatomic Particles 1️⃣ Boron is an element in Group 13 of the Periodic Table. a) Define the term "isotope." 🌟 b) Provide the number of i) protons, ii) neutrons, and iii) electrons in one neutral atom of the isotope 11B. 🧪 c) State the relative masses and charges of: i) an electron 🌌 ii) a neutron 🌌 iii) a proton 🌌 2️⃣ Zirconium (Zr) and hafnium (Hf) are metals. a) i) Write the isotopic symbol for the isotope of zirconium with 40 protons and 91 nucleons. 🌟 ii) How many neutrons are present in one atom of this isotope? 🌟 b) Hafnium ions, 18072Hf2+, are produced in a mass spectrometer. How many electrons are present in one of these hafnium ions? 🌟 c) Describe the behavior of a beam of protons passing through the gap between charged plates and explain what happens when a beam of neutrons passes through the same gap. 🌌 3️⃣ a) Describe the structure of an atom, including details of the subatomic particles present. 🌟 b) Explain the terms atomic number and nucleon number. 🌌 c) Copy and complete the table: Neutral atom | Atomic number | Nucleon number | Numbers of each subatomic particle present Mg | 12 | 24 | Al | 13 | 27 | d) Explain why atoms are neutral. 🌌 e) Explain why an oxygen atom cannot have 9 protons. 🌌 f) Explain why electrons are not used when calculating the relative mass of an atom. 🌌 4️⃣ The symbols below describe two isotopes of the element uranium. 235 92U 238 92U a) Define the term "isotope." 🌟 b) i) In what ways are these two isotopes of uranium identical? 🌟 ii) In what ways do they differ? 🌟 c) State the number of electrons present in one U2+ ion. 🌌 5️⃣ The table below shows the two naturally occurring isotopes of chlorine. a) Copy and complete the table: 35 17Cl 37 17Cl number of protons | number of electrons | number of neutrons | b) Based on the relative atomic mass of chlorine (35.5), what can you infer about the relative abundance of the two naturally occurring isotopes of chlorine? 🌟 c) i) Explain why a magnesium ion is positively charged. 🌌 ii) Explain why a chloride ion has a single negative charge. 🌌 Note: 🌟 indicates questions with fill-in-the-blank format, and 🌌 indicates multiple-choice questions. Good luck! 🧪🔬 Answers 1️⃣ Boron is an element in Group 13 of the Periodic Table. a) The term "isotope" refers to different forms of an element that have the same number of protons but different numbers of neutrons. b) i) Protons: 5, ii) Neutrons: 6, iii) Electrons: 5. 2️⃣ Zirconium (Zr) and hafnium (Hf) are metals. a) i) The isotopic symbol for the isotope of zirconium with 40 protons and 91 nucleons is 9123Zr. ii) The number of neutrons in one atom of this isotope is 51. b) The hafnium ion (18072Hf2+) contains 68 electrons. c) - i) The beam of protons passing through the gap between the charged plates is deflected towards the negative plate due to the electric field. ii) When a beam of neutrons passes through the gap between the charged plates, it remains unaffected as neutrons are neutral particles. 3️⃣ a) The structure of an atom consists of subatomic particles: protons and neutrons located in the nucleus, and electrons orbiting the nucleus. b) - Atomic number represents the number of protons in an atom's nucleus. Nucleon number (mass number) represents the total number of protons and neutrons in an atom's nucleus. c) Neutral atom | Atomic number | Nucleon number | Numbers of each subatomic particle present Mg | 12 | 24 | 12 protons, 12 neutrons, 12 electrons Al | 13 | 27 | 13 protons, 14 neutrons, 13 electrons d) Atoms are neutral because they have an equal number of protons and electrons, resulting in a net charge of zero. e) An oxygen atom cannot have 9 protons because the number of protons determines the element's identity, and oxygen is defined by having 8 protons. f) Electrons are not used when calculating the relative mass of an atom because their mass is significantly smaller compared to protons and neutrons. Their contribution to the total mass is negligible. 4️⃣ The symbols below describe two isotopes of the element uranium. 235 92U 238 92U a) The term "isotope" refers to different forms of an element that have the same number of protons but different numbers of neutrons. b) - i) These two isotopes of uranium are identical in terms of the number of protons (92) and the chemical properties. ii) They differ in terms of their mass number (235 and 238) and the number of neutrons. c) One U2+ ion has 90 electrons. 5️⃣ The table below shows the two naturally occurring isotopes of chlorine. a) 35 17Cl 37 17Cl number of protons | 17 | 17 number of electrons | 17 | 17 number of neutrons | 18 | 20 b) The relative atomic mass of 35.5 suggests that the two isotopes of chlorine have approximately equal abundance. c) - i) A magnesium ion is positively charged because it has lost two electrons, resulting in more protons than electrons. ii) A chloride ion has a single negative charge because it has gained one electron, resulting in more electrons than protons. Well done on completing the quiz! Keep up the great work! 🔬🎉 Quiz 2 : Atomic Structure, Isotopes, and Subatomic Particles 1️⃣ Boron is an element in Group 13 of the Periodic Table. a) Boron has two isotopes. 🔄❓ What do you understand by the term isotope ? [1] b) State the number of: i) protons, ii) neutrons, and iii) electrons in one neutral atom of the isotope 11 5B. [3] c) State the relative masses and charges of: i) an electron, ii) a neutron, and iii) a proton. [2] 2️⃣ Zirconium, Zr, and hafnium, Hf, are metals. An isotope of zirconium has 40 protons and 91 nucleons. ⚛️❓ a) i) Write the isotopic symbol for this isotope of zirconium. [1] ii) How many neutrons are present in one atom of this isotope? [1] b) Hafnium ions, 18072Hf2+ , are produced in a mass spectrometer. How many electrons are present in one of these hafnium ions? [1] c) The subatomic particles present in zirconium and hafnium are electrons, neutrons, and protons. A beam of protons is fired into an electric field produced by two charged plates, as shown in the diagram below: ) Describe how the beam of protons behaves when it passes through the gap between the charged plates. Explain your answer. [2] ii) Describe and explain what happens when a beam of neutrons passes through the gap between the charged plates. [2] 3️⃣ a) Describe the structure of an atom, giving details of the subatomic particles present. 🏢🔬 [6] b) Explain the terms: Atomic number, and Nucleon number. [2] c) Copy and complete the table: d) Explain why atoms are neutral. [1] e) An oxygen atom has 8 protons in its nucleus. Explain why it cannot have 9 protons. [1] f) When calculating the relative mass of an atom, the electrons are not used in the calculation. Explain why not. [1] 4️⃣ The symbols below describe two isotopes of the element uranium. 235 92U 238 92 U a) State the meaning of the term isotope . [1] b) i) In what ways are these two isotopes of uranium identical? [2] ii) In what ways do they differ? [2] c) In a mass spectrometer, uranium atoms can be converted to uranium ions, U2+ . State the number of electrons present in one U2+ ion. [1] 5️⃣ The table below shows the two naturally occurring isotopes of chlorine. a) Copy and complete the table: b) The relative atomic mass of chlorine is 35.5. What does this tell you about the relative abundance of the two naturally occurring isotopes of chlorine? [2] c) Magnesium chloride contains magnesium ions, Mg2+ , and chloride ions, Cl– . i) Explain why a magnesium ion is positively charged. [1] ii) Explain why a chloride ion has a single negative charge. [2] Total = 50 🌟 ✨ Quiz Answers: ✨ 1a) Isotope refers to different forms of an element with the same number of protons but different numbers of neutrons. 1b) i) Protons: 5, ii) Neutrons: 6, iii) Electrons: 5 1c) i) Electron: Relative mass = 1/1837 amu, Charge = -1 e ii) Neutron: Relative mass = 1 amu, Charge = 0 iii) Proton: Relative mass = 1 amu, Charge = +1 e 2a) i) 91Zr ii) Neutrons: 51 2b) Electrons: 72 2c) i) The beam of protons is deflected towards the negatively charged plate due to their positive charge. ii) Neutrons are electrically neutral, so they are not affected by the electric field and continue on a straight path. 3a) An atom consists of a nucleus (containing protons and neutrons) surrounded by electrons in energy levels or shells. 3b) - Atomic number: Number of protons in an atom's nucleus. - Nucleon number: Total number of protons and neutrons in an atom's nucleus. 3c) e) The number of protons determines the identity of an element. Changing the number of protons would result in a different element. f) Relative mass calculations focus on the mass of the nucleus, which is primarily determined by protons and neutrons. Electrons contribute negligible mass. 4a) Isotope refers to different forms of an element with the same number of protons but different numbers of neutrons. 4b) i) Both isotopes have the same number of protons (92) and belong to the element uranium. ii) They differ in the number of neutrons: Uranium-235 has 143 neutrons, while uranium-238 has 146 neutrons. 4c) U2+ ion has 90 electrons. 5a) | | 35 | 17 Cl | 37 | 17 b) The relative atomic mass of 35.5 indicates that there is a mixture of the two isotopes of chlorine, with a higher abundance of the isotope with a mass number of 35.c) i) A magnesium ion is positively charged because it has lost two electrons, resulting in a net positive charge. ii) A chloride ion has a single negative charge because it has gained one electron, resulting in a net negative charge.I hope you enjoyed the quiz! 🎉

< Back Previous Next Notes : ​ 1.1 States Of Matter 1.2 Changes in States of Matter ​ 1.3 Heating Curve 1.4 Diffusion 1.1 States Of Matter Notes : ​ State the distinguishing properties of solids liquids and gases ​ Matter in all states is made up of particles ​ Particles forming matter can be represented by small solid spheres. Back to Chapter 1 Menu Solid particles : have a regular arrangement and are close together They have a fixed pattern ; they only vibrate in their position. ​ Liquid particles : have a random arrangement they are close together They have no fixed pattern ; they slide past each other ​ Gas particles : have a random arrangement , they are far apart from each other and they have no fixed pattern or shape , they move rapidly and randomly. A Solid has a definite shape and volume but can not flow A Liquid has a definite volume but has no fixed shape as it takes the shape of the container and it can flow A Gas has no definite shape or volume , it can spread everywhere through the container

Heating Curve ​ ​ A graphical representation of the relationship between temperature and time as a substance is heated.

Effect of changing temperature on rate of reaction: Grade 10 SABIS ​ increasing the temperature increases the average kinetic energy of the reactant particles, the number of particles that collide with activation energy or more increases, thus the number of effective collisions increases and so does the rate. A second, not as important, effect is an increase in the collision frequency.

Reactivity of alkali metals increases as their atomic number increases. Grade 10 SABIS ​

Energy Conversion Grade 10 SABIS ​ Energy conversion refers to the process of transforming energy from one form to another. It involves the conversion of energy between different types, such as mechanical, electrical, thermal, chemical, or radiant energy. To understand energy conversion, let's consider an everyday example: a car. When you drive a car, the engine converts the chemical energy stored in fuel into mechanical energy to move the vehicle. Here, energy is transformed from the chemical form (fuel) to mechanical energy (motion). Another example of energy conversion is the use of solar panels to generate electricity. Solar panels convert radiant energy from the sun into electrical energy, which can be used to power homes, devices, or charge batteries. In a similar manner, a wind turbine converts the kinetic energy of the wind into electrical energy. The movement of the wind blades causes the rotor to spin, generating electricity through the conversion of kinetic energy to electrical energy. In thermodynamics, a steam power plant exemplifies energy conversion. Heat energy from burning fossil fuels or nuclear reactions is used to produce steam, which then drives a turbine to generate electrical energy. Here, the energy is converted from thermal energy to mechanical energy and finally to electrical energy. Energy conversion is also evident in the use of batteries. When you charge a battery, electrical energy from a power source is converted into chemical energy, which is stored in the battery for later use. When you use the battery, the stored chemical energy is then converted back into electrical energy. Furthermore, when you switch on a light bulb, electrical energy is converted into radiant energy (light) and thermal energy (heat) as the filament emits light and produces heat. In our bodies, food is converted into energy through a process called cellular respiration. The chemical energy stored in food molecules is transformed into usable energy in the form of adenosine triphosphate (ATP), which powers various biological processes. Energy conversion is essential in various industries and technologies. For example, in hydroelectric power plants, the potential energy of water stored in dams is converted into kinetic energy as it flows downhill, which is then transformed into electrical energy. In summary, energy conversion is the process of transforming energy from one form to another. Examples such as cars converting chemical energy to mechanical energy, solar panels converting radiant energy to electrical energy, and batteries converting electrical energy to chemical energy help illustrate the concept. Energy conversion plays a crucial role in various systems, technologies, and natural processes, enabling the utilization and transfer of energy in different forms for everyday applications.

Heating water from 20°C through to boiling continuously at 100°C Grade 10 SABIS SABIS Endothermic

Fractional Coefficients Grade 10 SABIS SABIS Coefficients in a chemical equation that are fractions, used to balance the equation.

Subscript Grade 10 SABIS SABIS The number used after a chemical symbol to indicate the number of atoms present per molecule

Application on Hess’s Law Grade 10 SABIS ​ Question 1: Given the following reactions and their respective enthalpy changes: C(graphite) + O2(g) → CO2(g) ΔH1 = -393.5 kJ/mol CO(g) + 1/2O2(g) → CO2(g) ΔH2 = -283.0 kJ/mol C(graphite) + 1/2O2(g) → CO(g) ΔH3 = -110.5 kJ/mol Calculate the enthalpy change for the reaction: C(graphite) + 1/2O2(g) → CO2(g) Answer 1: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Adding reactions 2 and 3 gives: 2CO(g) + O2(g) → 2CO2(g) ΔH2 + ΔH3 = -283.0 kJ/mol + (-110.5 kJ/mol) = -393.5 kJ/mol Since this reaction is the reverse of reaction 1, the enthalpy change for the given reaction is the negative of ΔH1. ΔH = -(-393.5 kJ/mol) = 393.5 kJ/mol Question 2: Given the following reactions and their respective enthalpy changes: N2(g) + O2(g) → 2NO(g) ΔH1 = 180.6 kJ/mol 1/2N2(g) + O2(g) → NO2(g) ΔH2 = 33.2 kJ/mol Calculate the enthalpy change for the reaction: NO(g) + NO2(g) → N2O3(g) Answer 2: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Multiplying reaction 2 by 2 gives: N2(g) + 2O2(g) → 2NO2(g) 2ΔH2 = 2(33.2 kJ/mol) = 66.4 kJ/mol Adding reactions 1 and 2 gives: 2N2(g) + 2O2(g) → 4NO(g) 2ΔH1 + 2ΔH2 = 2(180.6 kJ/mol) + 66.4 kJ/mol = 427.6 kJ/mol Since this reaction is the reverse of the desired reaction, the enthalpy change for the given reaction is the negative of the calculated value. ΔH = -427.6 kJ/mol Question 3: Given the following reactions and their respective enthalpy changes: 2H2(g) + O2(g) → 2H2O(l) ΔH1 = -572 kJ/mol 2H2O(l) → 2H2(g) + O2(g) ΔH2 = 572 kJ/mol Calculate the enthalpy change for the reaction: H2(g) + 1/2O2(g) → H2O(l) Answer 3: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add