Periodic Table Section

Here are the solutions to your questions: 1. Periodic Table Section a) Using the letters from the table, select an element that is: i) Stored in paraffin oil. Alkali metals (Group 1) are highly reactive and stored in paraffin oil. Element A is in Group 1. Answer: A ii) A reddish liquid at RTP. Bromine is a reddish-brown liquid at room temperature. Bromine is in Group 17, Period 4. The elements F (Group 17, Period 2) and G (Group 17, Period 3) are not Bromine. None of the elements A-H shown in the table fit this description. Answer: None of the elements shown b) Write the electronic configuration of: i) B: Element B is in Group 2, Period 2. This corresponds to Beryllium (Be), which has an atomic number of 4. Electronic configuration: 2, 2 (or 1s^2 2s^2) ii) Why is B classified in group II? Element B is classified in Group II because it has two valence electrons (two electrons in its outermost electron shell). c) The element, E, has a relative atomic mass of 27. Give the composition of an atom of E. If the relative atomic mass of element E is 27, then E is Aluminum (Al). Aluminum has an atomic number of 13. i) Number of protons: The atomic number equals the number of protons. Answer: 13 ii) Number of electrons: For a neutral atom, the number of electrons equals the number of protons. Answer: 13 iii) Number of neutrons: The number of neutrons is calculated by subtracting the number of protons from the relative atomic mass. Number of neutrons = Relative atomic mass - Number of protons Number of neutrons = 27 - 13 = 14 Answer: 14 d) Two elements X and Y have atomic numbers of 6 and 17 respectively. Element X (atomic number 6) is Carbon (C). Element Y (atomic number 17) is Chlorine (Cl). i) Write the formula of the compound formed between X and Y. Carbon (Group 14) typically forms 4 covalent bonds. Chlorine (Group 17) typically forms 1 covalent bond. To satisfy the valencies, one carbon atom will bond with four chlorine atoms. Formula: CCl_4 ii) Identify the bond type in the compound in d(i) above. Carbon and Chlorine are both non-metals. The bond formed between two non-metals is a covalent bond. Bond type: Covalent bond e) Sodium chloride has the formula NaCl. Identify the charge of the metallic ion: In Sodium chloride (NaCl), Sodium (Na) is the metallic ion. Sodium is in Group 1 and loses one electron to form a stable ion. Charge of the metallic ion: +1 (or Na^+) --- 2. Elements and Reactions Given elements: Sodium (Na), Silver (Ag), Calcium (Ca), Iron (Fe), Aluminium (Al). a) Select from the elements: i) A transition metal used as a catalyst. Iron (Fe) is a transition metal commonly used as a catalyst (e.g., in the Haber process). Answer: Iron (Fe) ii) An element that forms an amphoteric oxide. Amphoteric oxides react with both acids and bases. Aluminium (Al) forms an amphoteric oxide (Al_2O_3). Answer: Aluminium (Al) iii) An element that is a basic constituent of bones. Calcium (Ca) is a major component of bones, primarily in the form of calcium phosphate. Answer: Calcium (Ca) b) Arrange the elements in order of decreasing reactivity, starting from the most reactive. Based on the reactivity series, the order from most reactive to least reactive is: Order: Sodium (Na), Calcium (Ca), Aluminium (Al), Iron (Fe), Silver (Ag) c) The element Calcium (Ca) reacts with dilute hydrochloric acid. i) State one common observation. Calcium is a reactive metal that reacts with acids to produce hydrogen gas. Observation: Effervescence (fizzing or bubbling) ii) Write a balanced equation for the reaction taking place. Calcium reacts with hydrochloric acid to form calcium chloride and hydrogen gas. Ca(s) + 2HCl(aq) CaCl_2(aq) + H_2(g) Send me the next one 📸