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8bfcf45c-0f02-4192-a879-a9a474f59d01 Atomic Structure Summary Nuclear Atom : A nuclear atom is an atom with subatomic particles and a nucleus. Most of it is empty space. Atomic Boundaries : Atoms do not have specific boundaries. Atomic Diameter : The atomic diameter is the distance between two adjacent nuclei. It is in the order of 10^-10 m and it is about 10^4 times the diameter of the nucleus. Nuclear Diameter : The nuclear diameter is in the order of 10^-14 m. Subatomic Particles : Subatomic particles are electrons, protons, and neutrons. Atomic Nucleus : The atomic nucleus contains protons and neutrons (collectively known as nucleons). Comparison Between Subatomic Particles : Proton: +1 charge, 1 amu mass, located inside the nucleus. Neutron: 0 charge, 1 amu mass, located inside the nucleus. Electron: -1 charge, 1/1840 mass of 1 proton, located around the nucleus. Nuclear Atom : In a nuclear atom, the number of positive protons is equal to the number of negative electrons. Nuclear Charge : The nucleus is positively charged since it contains positive protons and neutral neutrons. Atomic Mass : The mass of an atom is concentrated in its nucleus; electrons have negligible mass compared to the nucleus. Neutrons : Neutrons help in binding the nucleus together (prevent protons from repelling each other). Nuclei of Same Element : Nuclei of the same element have the same atomic number (# of protons) and the same nuclear charge Nuclear Atom : Picture an atom as a tiny solar system. The nucleus is the sun, and the electrons are planets orbiting around it. But unlike our solar system, most of an atom is just empty space. It's like if the sun was in New York and the nearest planet was in Los Angeles! Atomic Boundaries : Atoms are like social butterflies. They don't have specific boundaries and are always ready to interact with their neighbors. It's like being at a party where everyone is mingling freely. Atomic Diameter : The atomic diameter is the distance between two adjacent atoms, like two friends standing shoulder to shoulder. It's incredibly small, about 10^-10 meters, which is a hundred million times smaller than the width of a human hair! Nuclear Diameter : The nuclear diameter is even smaller, about 10^-14 meters. That's like comparing the size of a marble to the size of the Earth! Subatomic Particles : Atoms are made up of even tinier particles: protons, neutrons, and electrons. It's like a Lego set, where the individual pieces (subatomic particles) come together to build the final product (the atom). Atomic Nucleus : The atomic nucleus is like the heart of the atom. It's where the protons and neutrons (collectively known as nucleons) live. It's the control center, holding the atom together and defining its identity. Comparison Between Subatomic Particles : Proton: Imagine protons as positive little suns residing in the nucleus. Neutron: Neutrons are the peacekeepers of the atom. They have no charge and hang out in the nucleus, helping to keep the protons from pushing each other away. Electron: Electrons are like speedy little planets orbiting the nucleus. They carry a negative charge and are incredibly light, with a mass about 1/1840 of a proton. Nuclear Atom : In a nuclear atom, the number of positive protons is equal to the number of negative electrons. It's like a perfectly balanced seesaw, with the same weight on both sides. Nuclear Charge : The nucleus carries a positive charge, thanks to the protons it houses. It's like a positive magnet at the center of the atom. Atomic Mass : The mass of an atom is concentrated in its nucleus, just like a peach pit holds most of the peach's weight. Electrons are so light, their mass is almost negligible. Neutrons : Neutrons are like the glue of the atom. They help hold the nucleus together and prevent the protons from repelling each other, just like a mediator in a heated debate. Nuclei of Same Element : Nuclei of the same element have the same number of protons and the same nuclear charge. It's like having a unique ID or barcode that identifies each element.

⚛️ Lesson 6 ⚛️ < Back Atomic Structure Lesson 6 ⚛️ Lesson 6 ⚛️ This quiz tests your knowledge of atomic structure, radii, and isotopes. Answer multiple-choice and fill-in-the-blank questions to demonstrate your understanding of these concepts and their significance in the world of chemistry. Good luck! 🧪🔬 Previous Next ⚛️Small Quiz Lesson 6⚛️ 🌱 1. What is the smallest part of an element that can participate in chemical reactions? 🤔 a) Neutron b) ⚛️ Proton c) ⚡️ Electron d) 🔬 Isotope 🌌 2. Where are protons and neutrons found in an atom? 📍 a) In the 🌑 nucleus b) In the electron cloud ☁️ c) In the orbitals 🌐 d) In the shells 🐚 ⚡️ 3. What is the charge of an electron? ⚡️ a) Positive ➕ b) Negative ➖ c) Neutral ⚖️ d) Variable 🔄 🎭 4. What do we call the particles that an atom is made up of? 🎭 a) Electrons 💫 b) Protons ⚛️ c) Neutrons 🌌 d) Isotopes 🔬 Fill in the Blanks: 💫 5. Electrons have __________ mass compared to protons and neutrons. Answer: 🌌 Negligible/lightweight 🌌 6. In a neutral atom, the number of electrons is equal to the number of __________. Answer: ⚛️ Protons 🌍 7. When it comes to chemical properties, isotopes of the same element exhibit strikingly similar behaviors due to the identical number of __________ in their outer shells. Answer: Electrons 📏 8. The atomic radius is half the distance between the nuclei of two bonded atoms and measures the __________ of an atom. Answer: Size 🧩 9. Atomic radii generally decrease as you move across each Period of the Periodic Table due to the increasing number of __________. Answer: Protons 🔄 10. If an atom loses electrons to become a positively charged ion (cation), its ionic radius __________. Answer: Decreases Keep up the great work with your learning journey! 🌟🔬💡 Multiple Choice Questions: 🌌 11. What creates an electric field that influences the movement of charged particles? a) 🧲 Magnetic fields b) 🌪️ Gravitational fields c) 🔋 Charged plates d) 🌈 Rainbow fields 🔬 12. What determines the identity of an element? a) Atomic mass b) Number of electrons c) Atomic number d) Number of neutrons 💪 13. What is the role of electrons in chemical reactions? a) Stabilizing the nucleus b) Determining the mass of the atom c) Participating in bonding d) Influencing the atomic radius 🌌 14. What happens to the charge of an atom if it loses an electron? a) Becomes positively charged b) Becomes negatively charged c) Remains neutral d) Varies depending on the atom 🌟 15. What are the charges of protons, neutrons, and electrons, respectively? a) +1, -1, 0 b) 0, +1, -1 c) +1, 0, -1 d) -1, 0, +1 Fill in the Blanks: ⚖️ 16. The number of neutrons in an atom can be calculated by subtracting the atomic number from the __________. Answer: Mass number 🔍 17. In an electric field, electrons are deflected __________ from the negative plate and toward the positive plate. Answer: 🌪️ Away 🧪 18. An element has a mass number of 63 and 29 protons. The number of neutrons in this element is __________. Answer: 34 🌠 19. The atomic number determines the position of an element in the __________. Answer: Periodic table 🌆 20. Ions are formed when atoms gain or lose __________. Answer: Electrons 🌌 21. Neutrons remain __________ by the charged plates in an electric field due to their neutral nature. Answer: 👏 Unaffected ⚛️ 22. Copper has an atomic number of 29. How many protons does a copper atom have? Answer: 29 📚 23. What do we call the particles that an atom is made up of? Answer: Subatomic particles 🌟 24. The electron's movement in an electric field showcases its __________ charge and small mass. Answer: 💫 Negative 💥 25. The number of protons (and electrons in a neutral atom) in an element with atomic number 17 is __________. Answer: 17 Great job so far! Keep up the momentum and continue exploring the fascinating world of atoms and their structures! 🚀🔭 Multiple Choice Questions: ⚛️ 26. What determines the identity of an element? a) Atomic radius b) Number of neutrons c) Mass number d) Atomic number 🌌 27. How does the arrangement of electrons impact the chemical properties of an atom? a) It determines the atomic mass. b) It affects the atomic radius. c) It determines the number of protons. d) It influences bonding and reactivity. 📚 28. What is the term for protons and neutrons together? a) Nucleons b) Ions c) Isotopes d) Electrons 💡 29. How can we calculate the number of neutrons in an atom? a) By subtracting the mass number from the atomic number. b) By adding the atomic number to the mass number. c) By subtracting the number of protons from the mass number. d) By adding the number of protons to the atomic number. ⚡ 30. What is the space called that electrons move around in, outside the nucleus? a) Electron cloud b) Orbital c) Nucleus d) Valence shell Fill in the Blanks: 🌈 31. The atomic number tells us the number of __________ in the nucleus of an atom. Answer: Protons ⚛️ 32. If an atom gains an electron, it becomes __________ charged because electrons carry a negative charge. Answer: Negatively 💪 33. The number of __________ determines the position of an element in the periodic table. Answer: Protons (atomic number) 🔬 34. The number of neutrons in an atom can be calculated by subtracting the __________ from the mass number. Answer: Atomic number 💫 35. Electrons have __________ mass compared to protons and neutrons. Answer: Negligible/lightweight 🌟 36. The atomic radius is half the distance between the nuclei of two __________ atoms bonded together. Answer: Identical/same ⚖️ 37. In a neutral atom, the number of electrons is equal to the number of __________. Answer: Protons 🌌 38. What is the charge of a neutral atom? Answer: Neutral/zero/0 🎭 39. Neutrons contribute to the __________ of an atom without affecting its charge. Answer: Mass 🌆 40. Atoms get adventurous and become charged cities called __________. Answer: Ions Fantastic progress! You're doing a great job exploring the intricate details of atomic structure. Let's continue uncovering more about atoms, their properties, and their behavior! 🧪🌟 Multiple Choice Questions: 🌟 41. What resides in the nucleus and holds nearly all of the atom's mass? a) Electrons b) Neutrons c) Protons d) Isotopes 🔋 42. What creates an electric field that influences the movement of charged particles? a) Atomic radius b) Neutrons c) Protons d) Charged plates 🌍 43. What causes the atomic radius to decrease as you travel across each Period in the periodic table? a) Increasing number of protons b) Increasing number of neutrons c) Increasing number of electrons d) Increasing number of shells ⚡ 44. If an atom loses electrons to become a positively charged ion, what happens to its ionic radius? a) It increases b) It decreases c) It remains the same d) It becomes neutral 🎯 45. What do isotopes of the same element share? a) Same number of protons and electrons b) Same number of neutrons and electrons c) Same number of protons and neutrons d) Same atomic mass Fill in the Blanks: 💥 46. The atomic radius generally __________ as you travel down each Group in the periodic table. Answer: Increases/grows/get larger 🌌 47. Atomic radii generally __________ as you travel across each Period in the periodic table. Answer: Decrease/get smaller 🔄 48. An atom becomes a positively charged ion (cation) when it loses __________. Answer: Electrons 🔄 49. An atom becomes a negatively charged ion (anion) when it gains __________. Answer: Electrons 🗺️ 50. Atomic and ionic radii offer a sort of "map" to the __________ of atoms and ions. Answer: Universe/microcosm/realm Well done! You're making great progress in understanding atomic structure, radii, and the behavior of atoms and ions. Keep up the fantastic work, and let's continue exploring the fascinating world of chemistry together! 🌌🧪🌟

< Back Unit 1 AP Chemistry Topic 3 Elements and Mixtures 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 3 Elements and Mixtures Previous Next

STP, Volume Ratios, Energy in Reactions, and Limiting Reagents Chapter 4 SABIS Grade 10 Part 4 STP, Volume Ratios, Energy in Reactions, and Limiting Reagents ✅ Lesson 19: ✅ STP, Volume Ratios, Energy in Reactions, and Limiting Reagents Hello learners! 🌞🎒 Today's chemistry class is going to be a thrilling ride as we explore concepts like Standard Temperature and Pressure (STP), stoichiometric calculations, and limiting reagents. Buckle up and get ready! 🚀🔬💡 Prerequisite Material Quiz 📚🧠 What does STP stand for? What are the conditions for STP? True or False: At STP, 1.00 mole of any gas occupies 22.4 dm³. How much percentage of air is oxygen gas by volume? What is a limiting reagent in a chemical reaction? Can the volume ratio at STP be used for any given reaction equation? True or False: The limiting reagent determines how much of the other reactants will be consumed in a chemical reaction. Can we write an equation including the energy required or released? True or False: A limiting reagent gets completely used up in a chemical reaction. Can we solve problems using the volume ratio? (Answers at the end of the lesson) Explanation: STP, Volume Ratios, Energy in Reactions, and Limiting Reagents 🧐👩🔬 Standard Temperature and Pressure (STP) STP is a common set of conditions for gases defined as 0 degrees Celsius and 1.00 atmosphere pressure. Under these conditions, any gas will have a volume of 22.4 dm³ per mole. Volume Ratios In gas reactions at STP, the volumes of gases involved can be directly related to the coefficients in the balanced equation. These are the volume ratios. Energy in Reactions Chemical reactions either absorb or release energy. We can represent this energy change in the chemical equation. Limiting Reagents In a chemical reaction, the limiting reagent is the substance that gets completely consumed and determines the maximum amount of product that can be formed. Examples 🌍🔬🔎 STP and volume ratios : In the reaction 2H₂(g) + O₂(g) → 2H₂O(g), the volume ratio of hydrogen to oxygen to water vapor is 2:1:2. If we start with 44.8 dm³ of hydrogen gas at STP, we would expect to produce 44.8 dm³ of water vapor, assuming oxygen is not the limiting reagent. Energy in reactions : In the combustion of methane (exothermic reaction), energy is released: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) + energy. Limiting reagents : If we react 4 moles of hydrogen gas with 1 mole of nitrogen gas according to the equation N₂(g) + 3H₂(g) → 2NH₃(g), hydrogen is the limiting reagent. It will be completely consumed and determine the maximum amount of ammonia that can be produced (2 moles). Post-lesson MCQs 📝✅ True or False: At STP, all gases have the same volume per mole. What is the volume ratio of hydrogen to oxygen in the balanced equation for the formation of water? Can energy be a product in a chemical reaction? True or False: The limiting reagent in a reaction is always the reactant with the smallest amount of moles. How do we determine the mass of the excess reagent left in a reaction? (Answers at the end of the lesson) Answers Prerequisite Material Quiz : Standard Temperature and Pressure, 0 degrees Celsius and 1.00 atmosphere pressure, True, 20%, The substance that gets completely consumed in a reaction, Yes, True, Yes, True, Yes. Post-lesson MCQs : True, 2:1, Yes, energy can be a product in exothermic reactions, False, the limiting reagent is the substance that is completely consumed in a reaction, not necessarily the one with the smallest amount of moles, By subtracting the amount of the reagent that reacted from the total amount initially present. Complete the Questions : The volume ratio at STP for a given reaction equation is directly related to the coefficients of the gases in the balanced equation. An example of an endothermic reaction is the thermal decomposition of calcium carbonate: CaCO₃(s) + energy → CaO(s) + CO₂(g). The volume of 2 moles of nitrogen gas at STP is 2 moles × 22.4 dm³/mole = 44.8 dm³. Stoichiometric calculations involve using the coefficients in a balanced equation to calculate quantities of reactants or products. It can involve mole, mass, volume, or energy ratios. The limiting reagent is determined by comparing the amount of products each reactant could produce if it were completely consumed. The reactant that produces the least amount of product is the limiting reagent.

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Lesson 47 Chapter 8 SABIS Grade 10 Part 3 Lesson 47 Chapter 8 Third Lesson : 🔗 Chemical Bond Energy and Energy Changes in Substances Part 1: 🔍 Chemical Bond Energy 8.2.3 Variation of Potential Energy as Two H Atoms Approach 💫 Approaching Hydrogen Atoms Let's observe the dance of potential energy as two hydrogen atoms get closer and form a bond! 🕺💃 Sample Question 16 🧠 Understanding the Potential Energy Changes When two hydrogen atoms approach each other from an infinite distance: a) Initially, their total potential energy decreases because the attractive forces are initially stronger. b) Initially, their total potential energy increases because the attractive forces are initially stronger. c) At a certain distance, the potential energy of the atoms reaches a minimum value, and this distance is called the bond length. d) At a certain distance, the potential energy of the atoms reaches a maximum value, and this distance is called the bond length. e) If the two atoms approach closer than the bond length, the potential energy of the system increases rapidly. Sample Question 17 🧠 Bond Energy of the Hydrogen Molecule When two hydrogen atoms form a bond, bond energy is the energy needed to: a) Bring the two nuclei to touch each other. b) Make the distance between the two nuclei infinite. c) Burn the hydrogen to water. d) Change them to H2 gas. e) Tie the two hydrogen atoms together. Part 2: 🔍 Bond Energy and Energy Changes in Molecules 8.2.4 Vibrational Energy of Molecules 🎯 Vibrational Energy Let's explore how molecules vibrate with energy! It's like witnessing a molecular dance party in motion! 🎉 8.2.5 Rotational Energy of Molecules 🌀 Rotational Energy Molecules not only vibrate but also spin around! It's like watching tiny molecular acrobats perform graceful spins! 🤸 8.2.6 Heat Content 🌡️ Measuring Heat Content The heat content of a substance is like its inner energy bank, storing energy from various sources! 💰 8.2.7 Motion of Particles of an Ideal Gas 🚀 Motion of Gas Particles In the world of gases, particles zoom around at incredible speeds, like energetic little rockets in motion! 🚀 8.2.8 Energy Changes on Warming 🔥 Energy Changes During Warming As we warm up substances, energy swirls and transforms, like awakening the hidden potential within! 🌪️ Sample Question 18 🧠 Microscopic Changes When a Solid is Warmed Which of the following changes take place when a solid is warmed? a) Warming the solid increases the kinetic energy of the back-and-forth motions of the molecules about their regular crystal positions. b) If the solid is heated a little more, this random movement can destroy some of the nuclei of the atoms. c) At the temperature above which the kinetic energy of the particles causes so much random movement that the lattice is no longer stable, a phase change occurs: the solid melts. Sample Question 19 🧠 Microscopic Changes When a Liquid is Warmed Which of the following changes take place when a liquid is warmed? a) Warming the liquid increases the kinetic energy of the back-and-forth motions of the molecules to the extent where a molecule can move within the liquid from place to place. b) If the liquid is heated a little more, this random movement can destroy some of the nuclei of the atoms. c) At the temperature above which the kinetic energy of the particles causes so much random movement that the molecules of the liquid can move far from each other, a phase change occurs: the liquid evaporates. Sample Question 20 🧠 Microscopic Changes When Gases are Heated Strongly Which of the following changes take place when a gas is heated strongly? a) Warming the gas to the extent where the vibrational energy becomes equal to or more than the bond energy between atoms, the atoms move far apart. b) At temperatures higher than 6000K, the only molecules that can exist are those that have between 2 and 10 atoms. c) At temperatures that reach millions of degrees, nuclear reactions can take place. Sample Question 21 🧠 Relative Magnitude of Heat Involved in Physical & Chemical Changes Which of the following is correct about the relative magnitude of the heat involved in physical and chemical changes? a) Phase changes usually involve energies of tens of kilojoules per mole. b) Chemical reactions usually involve energies of tens of kilojoules per mole. c) Chemical reactions usually involve energies of about a thousand kilojoules per mole. d) Chemical reactions usually involve energies of several million kilojoules per mole. e) Chemical reactions usually involve energies of several hundred to several thousand kilojoules per mole. Thus, we see that the energies involved in chemical reactions are usually 10 to 100 times larger than those involved in phase changes. Congratulations! 🎉 You've completed Lesson 3 and explored the fascinating world of chemical bond energy, energy changes in substances, and the dance of molecules. Keep up the excellent work, and get ready to dive deeper into the captivating realm of chemistry! 🧪🚀

f55b1c1c-29e9-45a4-862f-2af67e06c626 Measurements and Calculations Calculations with Significant Figures Examples Summary

4cf9f06c-ad90-48c9-b5c5-b99c024c680e Subscripts Summary The small numbers written at the lower right of a chemical symbol, indicating the number of atoms of that element in the molecule.

c8a6b7b3-2eb0-4c94-b41f-82543171591c Recognizing the Reverse Reaction in Thermochemistry Summary Recognizing the reverse of an equation Write the reverse of the equation 2C(s) + 3H2 (g) → C2H6 (g) ΔH = − 84.5 kJ C2H6 (g) → 2C(s) + 3H2 (g) ΔH = + 84.5 kJ In thermochemistry, it is important to understand that chemical reactions can proceed in both the forward and reverse directions. The reverse reaction is simply the opposite of the forward reaction, where the products become the reactants, and the reactants become the products. To recognize the reverse of an equation, we look at the reactants and products and interchange their positions. In this case, the given equation is: 2C(s) + 3H2(g) → C2H6(g) ΔH = -84.5 kJ To write the reverse equation, we switch the positions of the reactants and products: C2H6(g) → 2C(s) + 3H2(g) ΔH = +84.5 kJ By reversing the equation, we also reverse the sign of the heat of reaction (∆H). In the original equation, the heat of reaction is -84.5 kJ, indicating that the reaction releases 84.5 kJ of heat energy. In the reverse equation, the heat of reaction becomes +84.5 kJ, indicating that the reaction now absorbs 84.5 kJ of heat energy. It's important to note that the reverse reaction occurs under different conditions compared to the forward reaction. While the forward reaction may be exothermic (releasing heat), the reverse reaction becomes endothermic (absorbing heat) due to the change in the sign of the heat of reaction. Understanding the reverse of an equation is crucial in thermochemistry, as it allows us to recognize that a reaction can proceed in both directions depending on the prevailing conditions. The reverse reaction is often observed when the products of a reaction have a higher concentration or are removed from the system, causing the reaction to shift towards the reactants. In summary, recognizing the reverse of an equation involves interchanging the positions of the reactants and products and changing the sign of the heat of reaction (∆H). In the given example, the reverse of the equation 2C(s) + 3H2(g) → C2H6(g) with a heat of reaction of -84.5 kJ is C2H6(g) → 2C(s) + 3H2(g) with a heat of reaction of +84.5 kJ. Understanding the reverse reaction is essential in thermochemistry to comprehend the bidirectional nature of chemical reactions and the associated heat changes.

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db405a4c-d3b4-49bc-b7e6-118eca8a1e32 Reaction of Alkali metals with hydrogen. Summary Generally: 2M(s) + 2H2(g) → 2MH(s) alkali metal + hydrogen → alkali metal hydride