8 Science Quarter 3_Weeks 7-8 PERIODIC TABLE OF ELEMENTS Learner’s Activity Sheet Photo Credit: Periodic Table: The Deadly and Life-giving Elements of Group 15 (newsweek.com) February 20, 2022 Science – Grade 8 Activity Worksheet Quarter 3 – Chemistry First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this book are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. OVERVIEW The periodic table of elements is the collective logical arrangement of elements in tabular form. Elements are arranged according to their atomic number, electronic configuration, and chemical properties. But how do early chemists come up with an idea of arranging the elements? History and Development of Periodic Table In 1817, a German chemist, Johann Wolfgang Dobereiner discovered that the atomic weight of strontium is in between the atomic weight of calcium and barium. He termed this arrangement as triads, in which the atomic mass of the of the third element is equal to the average of the first and second element. In 1864, a British chemist, John Alexander Newlands proposed that elements if organized in increasing atomic mass, can also be arranged by groups of eight. He termed this as the law of octaves- the same arrangement of musical scale. In 1869, a Russian chemist, Dmitri Ivanovich Mendeleev proposed his periodic law. He suggested that elements when arranged in increasing atomic mass, will also classified according to the chemical periodicity. Mendeleev’s first periodic table of elements was published in the same year supplied column for elements which do not fit in the group and leave some spaces due to his prediction of undiscovered elements. In the same year, another German chemist, Julian Lothar Meyer also created a periodic table which almost have the same assumption as Mendeleev but consist of only 28 elements. Meyer and Mendeleev were distinguished as the proponents of periodic table, however more credit was given to Mendeleev due to accuracy of his periodic table and prediction of properties of undiscovered elements. In 1914, a British chemist, Henry Gwyn Jeffreys Moseley arranged the elements into increasing atomic number. His experimentation showed that the x-rays omitted a frequency that is related to the increasing atomic number. The modern periodic table of elements are arranged again based on the modern periodic law, which declares that atomic number are the periodic function of the elements’ physical and chemical properties. Trends in the Periodic Table Elements in the periodic table are organized in patterns illustrating most of their chemical properties, is called as periodic trends. There are five (5) periodic trends namely: electronegativity, ionization energy, electron affinity, atomic radius, and metallic character. The columns are named as groups or families, and rows are called as periods or series. 1. Electronegativity is the measure of an atom to attract and attach electrons to itself. Electronegativity increases when going from left to right of the periodic table and decreases when going down in the periodic table. Fluorine is the most electronegative element. 2. Ionization energy is the least possible energy necessary to eliminate an electron from a gaseous atom at its ground state. The electron nearest to the nucleus of an atom is the one that has the greatest amount of energy due to the strong attraction of this electron to the positively charged nucleus. The ionization energy increases when going from left to right and decreases when going down. 3. Electron affinity is the tendency of an atom to accept an electron. The electron affinity increases when metallic property decreases, going from left to right of the periodic table. It decreases when going down a group. 4. Atomic radius is calculated using the distance between two nuclei of adjacent atoms of the same element and dividing the distance by 2. The atomic radius increases when going down the periodic table and decreases when going to the right. 5. Metallic character is defined as how prepared an atom can lose an electron. As an element becomes more metallic, it has the tendency to lose an electron. It the element becomes more non-metallic it has the tendency to accept electrons. The metallic property increases from right to left and when going down the group. The trend for non-metallic property is the opposite of the trend for metallic property. Content Standards: • The learners demonstrate understanding of identity of the periodic table of elements as an organizing tool to determine the chemical properties of elements. Performance Standards: • The learners should be able to present how water behaves in its different states within the water cycle. Most Essential Learning Competency: • Use the periodic table to predict a chemical behavior of an element. S8MT-IIIi-g-12 For the learner: This worksheet contains activities about the characteristics of an element. You may answer directly to this activity sheets and make sure to follow the directions stated in each part of the activity. Answer all questions the best that you can and please write legibly. For the parents: Learners may require your guidance in following the directions and answering the questions in each part of the activity. Make sure that they answer each part of the worksheet. Objective/s: • Determining the chemical characteristics of an element. ACTIVITY #1 – ODD ONE OUT WHAT I NEED (MATERIALS) ▪ Worksheet ▪ Pen WHAT TO DO (PROCEDURE) Part A: Color the symbol of element that is being described by each statement. H I Cl Pb Bi Al B Nb As Al Li Te Ar Tl Pb Ga C Ta N P Na Xe S Hg Po Si N V P Si non-metal element member of noble gas member of halogen family member of transition metals metalloid largest atomic radius gas at room temperature largest atomic number smallest ionization energy greatest electron affinity Guide Questions: 1. Describe what is atomic radius. 2. What is the atomic number of Vanadium? 3. How do you arrange the elements according to decreasing electron affinity? 4. How do you know that an element is a metalloid? 5. When will ionization energy increases in the periodic table? WHAT I CAN DO ABOUT IT (APPLICATION) Imagine yourself as an element. What element could that be and why? For the learner: This worksheet contains activities atoms and the trends in the periodic table. You may answer directly to this activity sheets and make sure to follow the directions stated in each part of the activity. Answer all questions the best that you can and please write legibly. For the parents: Learners may require your guidance in following the directions and answering the questions in each part of the activity. Make sure that they answer each part of the worksheet. Objectives: • Describe and predict the element’s trend in the periodic table. ACTIVITY #2 – PERIODIC TRENDS WHAT I NEED (MATERIALS) ▪ ▪ worksheets writing and coloring materials WHAT TO DO (PROCEDURE) Part A: Arrange the given elements according to the given trend: 1. In each of the following set of atoms, arrange them from lowest to highest electronegativity. a. Li, C, N b. C, O, Ne c. Si, P, O d. K, Mg, P e. S, F, He 2. In each of the following set of atoms, arrange them from lowest to highest ionization energy. a. Mg, Si, S b. Mg, Ca, Ba c. F, Cl, Br d. Ba, Cu, Ne e. Si, P, He 3. In each of the following set of atoms, arrange them from smallest to largest atomic radius. a. Ba, Cu, Zn b. F, Cl, Br c. Mg, Ca, Ba d. Mg, Si, S e. Si, P, O 4. In each of the following set of atoms, arrange them from increasing electron affinity. a. Li, C, F b. Li, Na, K c. Ge, P, O d. A, N, Al e. Al, Cl, Ga Part B: Answer the questions below. Use the given series and group of elements. Series 6: Ba Re Pt Au Po 1. Which has the highest ionization energy? 2. Which has the biggest atomic radius? 3. Which is the most electronegative? 4. Which is the most metallic? 5. Which is the most nonmetallic? 6. Which has the highest electron affinity? Group 17: F Cl 1. Which has the highest ionization energy? 2. Which has the biggest atomic radius? 3. Which is the most electronegative? 4. Which is the most metallic? 5. Which is the most nonmetallic? 6. Which has the highest electron affinity? Br I At For the learner: This worksheet contains activities about trends in the periodic table. You may answer directly to this activity sheets and make sure to follow the directions stated in each part of the activity. Answer all questions the best that you can and please write legibly. For the parents: Learners may require your guidance in following the directions and answering the questions in each part of the activity. Make sure that they answer each part of the worksheet. Objectives: • • Build three (3) dimensional graphs about the given periodic trend. Explain the how these trends increases or decreases. ACTIVITY #1 – CONSTRUCTING 3D MODEL OF ATOMIC RADIUS WHAT I NEED (MATERIALS) ▪ ▪ ▪ Clay/ playdough/ styroboard/ soft carton scissor/ cutter coloring materials ▪ ▪ worksheet toothpick/ stick / spaghetti noodles WHAT TO DO (PROCEDURE) 1. Using a scissor or cutter, Cut the toothpick/ stick/ spaghetti noodles into the following dimensions: 1.5 cm, 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 5 cm, 2. Color the different dimensions according to the following: 1.5 cm= red, 2 cm= orange, 2.5 cm= yellow and vice versa. 3. If using a clay/ playdough, massage it to make a ball then flatten it using your hands. When using a Styrofoam board/ soft carton, you don’t need to cut it, but make sure that the size of your styrofoam board and the flatten clay or playdough is the same with the size of the periodic table. (see attachment on the next pages) 4. Lay the copy of the periodic table on the top of the clay/play dough or styrofoam board/ soft carton. 5. You will be asked to arrange some elements according to the few trends using the given items. 1. Ar Al Cl P Si S Mg Analysis: a. Use the materials to arrange the following according to decreasing ionization energy. Attach the picture here. b. Use the materials to show the arrangement of the elements according to increasing metallic property. Attach the picture here. c. Draw the trend for decreasing metallic property. d. As the atomic number increases down the period, what happens to the electronegativity and why? 2. Radon Ytrium Antimony Manganese Curium Palladium Livermorium Analysis: a. Use the materials to arrange the following according to increasing electron affinity. Attach the picture here. b. Use the materials to show the arrangement of the elements according to decreasing electronegativity. Attach the picture here. c. Draw the trend for increasing atomic radius. d. As the atomic number increases down the period, what happens to the metallic property and why? REFERENCES: • https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Modules_and_Websites_(In organic_Chemistry)/Descriptive_Chemistry/Periodic_Trends_of_Elemental_Properties/Pe riodic_Trends#:~:text=Major%20periodic%20trends%20include%3A%20electronegativit y,quickly%20predict%20an%20element%27s%20properties. • https://www.asbmb.org/asbmb-today/science/020721/a-brief-history-of-the-periodic-table • http://www.friendlychemistry.com/lesson-10.html • https://www.khanacademy.org/science/chemistry/periodic-table • https://www.youtube.com/watch?v=ds-s59DrvIk
