Hydrogen and Alkali Metals
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An Alternate Graphical Representation of Periodic Table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt
An Alternate Graphical Representation of Periodic table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt. Ltd, Hyderabad, India. [email protected] Abstract Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2) SU(2) group. IUPAC, the governing body in Chemistry, doesn‟t approve any periodic table as a standard periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as „Circular form of Periodic table‟. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables. 1. Introduction The profoundness of inherent symmetry in nature can be seen at different depths of atomic scales. Periodic table symbolizes one such elegant symmetry existing within the atomic structure of chemical elements. This so called „symmetry‟ within the atomic structures has been widely studied from different prospects and over the last hundreds years more than 700 different graphical representations of Periodic tables have emerged [1]. Each graphical representation of chemical elements attempted to portray certain symmetries in form of columns, rows, spirals, dimensions etc. Out of all the graphical representations, the rectangular form of periodic table (also referred as Long form of periodic table or Modern periodic table) has gained wide acceptance. -
Unit 3 Notes: Periodic Table Notes John Newlands Proposed an Organization System Based on Increasing Atomic Mass in 1864
Unit 3 Notes: Periodic Table Notes John Newlands proposed an organization system based on increasing atomic mass in 1864. He noticed that both the chemical and physical properties repeated every 8 elements and called this the ____Law of Octaves ___________. In 1869 both Lothar Meyer and Dmitri Mendeleev showed a connection between atomic mass and an element’s properties. Mendeleev published first, and is given credit for this. He also noticed a periodic pattern when elements were ordered by increasing ___Atomic Mass _______________________________. By arranging elements in order of increasing atomic mass into columns, Mendeleev created the first Periodic Table. This table also predicted the existence and properties of undiscovered elements. After many new elements were discovered, it appeared that a number of elements were out of order based on their _____Properties_________. In 1913 Henry Mosley discovered that each element contains a unique number of ___Protons________________. By rearranging the elements based on _________Atomic Number___, the problems with the Periodic Table were corrected. This new arrangement creates a periodic repetition of both physical and chemical properties known as the ____Periodic Law___. Periods are the ____Rows_____ Groups/Families are the Columns Valence electrons across a period are There are equal numbers of valence in the same energy level electrons in a group. 1 When elements are arranged in order of increasing _Atomic Number_, there is a periodic repetition of their physical and chemical -
The Periodic Table
THE PERIODIC TABLE Dr Marius K Mutorwa [email protected] COURSE CONTENT 1. History of the atom 2. Sub-atomic Particles protons, electrons and neutrons 3. Atomic number and Mass number 4. Isotopes and Ions 5. Periodic Table Groups and Periods 6. Properties of metals and non-metals 7. Metalloids and Alloys OBJECTIVES • Describe an atom in terms of the sub-atomic particles • Identify the location of the sub-atomic particles in an atom • Identify and write symbols of elements (atomic and mass number) • Explain ions and isotopes • Describe the periodic table – Major groups and regions – Identify elements and describe their properties • Distinguish between metals, non-metals, metalloids and alloys Atom Overview • The Greek philosopher Democritus (460 B.C. – 370 B.C.) was among the first to suggest the existence of atoms (from the Greek word “atomos”) – He believed that atoms were indivisible and indestructible – His ideas did agree with later scientific theory, but did not explain chemical behavior, and was not based on the scientific method – but just philosophy John Dalton(1766-1844) In 1803, he proposed : 1. All matter is composed of atoms. 2. Atoms cannot be created or destroyed. 3. All the atoms of an element are identical. 4. The atoms of different elements are different. 5. When chemical reactions take place, atoms of different elements join together to form compounds. J.J.Thomson (1856-1940) 1. Proposed the first model of the atom. 2. 1897- Thomson discovered the electron (negatively- charged) – cathode rays 3. Thomson suggested that an atom is a positively- charged sphere with electrons embedded in it. -
Power Sources Challenge
POWER SOURCES CHALLENGE FUSION PHYSICS! A CLEAN ENERGY Summary: What if we could harness the power of the Sun for energy here on Fusion reactions occur when two nuclei come together to form one Earth? What would it take to accomplish this feat? Is it possible? atom. The reaction that happens in the sun fuses two Hydrogen atoms together to produce Helium. It looks like this in a very simplified way: Many researchers including our Department of Energy scientists and H + H He + ENERGY. This energy can be calculated by the famous engineers are taking on this challenge! In fact, there is one DOE Laboratory Einstein equation, E = mc2. devoted to fusion physics and is committed to being at the forefront of the science of magnetic fusion energy. Each of the colliding hydrogen atoms is a different isotope of In order to understand a little more about fusion energy, you will learn about hydrogen, one deuterium and one the atom and how reactions at the atomic level produce energy. tritium. The difference in these isotopes is simply one neutron. Background: It all starts with plasma! If you need to learn more about plasma Deuterium has one proton and one physics, visit the Power Sources Challenge plasma activities. neutron, tritium has one proton and two neutrons. Look at the The Fusion Reaction that happens in the SUN looks like this: illustration—do you see how the mass of the products is less than the mass of the reactants? That is called a mass deficit and that difference in mass is converted into energy. -
Chapter 7 Electron Configuration and the Periodic Table
Chapter 7 Electron Configuration and the Periodic Table Copyright McGraw-Hill 2009 1 7.1 Development of the Periodic Table • 1864 - John Newlands - Law of Octaves- every 8th element had similar properties when arranged by atomic masses (not true past Ca) • 1869 - Dmitri Mendeleev & Lothar Meyer - independently proposed idea of periodicity (recurrence of properties) Copyright McGraw-Hill 2009 2 • Mendeleev – Grouped elements (66) according to properties – Predicted properties for elements not yet discovered – Though a good model, Mendeleev could not explain inconsistencies, for instance, all elements were not in order according to atomic mass Copyright McGraw-Hill 2009 3 • 1913 - Henry Moseley explained the discrepancy – Discovered correlation between number of protons (atomic number) and frequency of X rays generated – Today, elements are arranged in order of increasing atomic number Copyright McGraw-Hill 2009 4 Periodic Table by Dates of Discovery Copyright McGraw-Hill 2009 5 Essential Elements in the Human Body Copyright McGraw-Hill 2009 6 The Modern Periodic Table Copyright McGraw-Hill 2009 7 7.2 The Modern Periodic Table • Classification of Elements – Main group elements - “representative elements” Group 1A- 7A – Noble gases - Group 8A all have ns2np6 configuration(exception-He) – Transition elements - 1B, 3B - 8B “d- block” – Lanthanides/actinides - “f-block” Copyright McGraw-Hill 2009 8 Periodic Table Colored Coded By Main Classifications Copyright McGraw-Hill 2009 9 Copyright McGraw-Hill 2009 10 • Predicting properties – Valence -
Unique Properties of Water!
Name: _______ANSWER KEY_______________ Class: _____ Date: _______________ Unique Properties of Water! Word Bank: Adhesion Evaporation Polar Surface tension Cohesion Freezing Positive Universal solvent Condensation Melting Sublimation Dissolve Negative 1. The electrons are not shared equally between the hydrogen and oxygen atoms of water creating a Polar molecule. 2. The polarity of water allows it to dissolve most substances. Because of this it is referred to as the universal solvent 3. Water molecules stick to other water molecules. This property is called cohesion. 4. Hydrogen bonds form between adjacent water molecules because the positive charged hydrogen end of one water molecule attracts the negative charged oxygen end of another water molecule. 5. Water molecules stick to other materials due to its polar nature. This property is called adhesion. 6. Hydrogen bonds hold water molecules closely together which causes water to have high surface tension. This is why water tends to clump together to form drops rather than spread out into a thin film. 7. Condensation is when water changes from a gas to a liquid. 8. Sublimation is when water changes from a solid directly to a gas. 9. Freezing is when water changes from a liquid to a solid. 10. Melting is when water changes from a solid to a liquid. 11. Evaporation is when water changes from a liquid to a gas. 12. Why does ice float? Water expands as it freezes, so it is LESS DENSE AS A SOLID. 13. What property refers to water molecules resembling magnets? How are these alike? Polar bonds create positive and negative ends of the molecule. -
Of the Periodic Table
of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use. -
Lithium Hydride Powered PEM Fuel Cells for Long-Duration Small Mobile Robotic Missions
Lithium Hydride Powered PEM Fuel Cells for Long-Duration Small Mobile Robotic Missions Jekanthan Thangavelautham, Daniel Strawser, Mei Yi Cheung Steven Dubowsky Abstract— This paper reports on a study to develop power supplies for small mobile robots performing long duration missions. It investigates the use of fuel cells to achieve this objective, and in particular Proton Exchange Membrane (PEM) fuel cells. It is shown through a representative case study that, in theory, fuel cell based power supplies will provide much longer range than the best current rechargeable battery technology. It also briefly discusses an important limitation that prevents fuel cells from achieving their ideal performance, namely a practical method to store their fuel (hydrogen) in a form that is compatible with small mobile field robots. A very efficient Fig. 1. Example of small robots (Left) A ball shaped hopping robot concept fuel storage concept based on water activated lithium hydride for exploration of extreme terrains and caves developed for NASA. (Right) (LiH) is proposed that releases hydrogen on demand. This iRobot 110 Firstlook used for observation, security and search and rescue. concept is very attractive because water vapor from the air is passively extracted or waste water from the fuel cell is recycled and transferred to the lithium hydride where the hydrogen is the near future. Hence, new means for powering field robots “stripped” from water and is returned to the fuel cell to form more water. This results in higher hydrogen storage efficiencies need to be considered. than conventional storage methods. Experimental results are This paper explores the use of fuel cells, and in particular presented that demonstrate the effectiveness of the approach. -
Hydrogen, Nitrogen and Argon Chemistry
Hydrogen, Nitrogen and Argon Chemistry Author: Brittland K. DeKorver Institute for Chemical Education and Nanoscale Science and Engineering Center University of Wisconsin-Madison Purpose: To learn about 3 of the gases that are in Earth’s atmosphere. Learning Objectives: 1. Understand that the atmosphere is made up of many gases. 2. Learn about the differences in flammability of nitrogen and hydrogen. 3. Learn what is produced during electrolysis. Next Generation Science Standards (est. 2013): PS1.A: Structure and Properties of Matter PS1.B: Chemical Reactions PS3.D: Energy in Chemical Processes and Everyday Life (partial) ETS1.A: Defining Engineering Problems ETS1.B: Designing Solutions to Engineering Problems ETS1.C: Optimizing the Design Solution National Science Education Standards (valid 1996-2013): Physical Science Standards: Properties and changes of properties in matter Earth and Space Science Standards: Structure of the earth system Suggested Previous Activities: Oxygen Investigation and Carbon Dioxide Chemistry Grade Level: 2-8 Time: 1 hour Materials: Safety glasses Manganese dioxide Work gloves (for handling Tea-light candles steel wool) Matches Test tubes Spatulas Beakers Wooden splints 100mL graduated cylinders Waste bucket for burnt 15mL graduated cylinders materials 3% hydrogen peroxide Vinegar Baking soda Safety: 1. Students should wear safety glasses during all activities. 2. Students should not be allowed to use matches or candle. 3. Students should be cautioned to only mix the chemicals as directed. Introduction: Air refers to the mixture of gases that make up the Earth’s atmosphere. In this lesson, students will learn about hydrogen (present in very, very small amounts in our atmosphere), nitrogen (the most prevalent gas), and argon (third behind nitrogen and oxygen.) Procedures: 1. -
MODULE 11: GLOSSARY and CONVERSIONS Cell Engines
Hydrogen Fuel MODULE 11: GLOSSARY AND CONVERSIONS Cell Engines CONTENTS 11.1 GLOSSARY.......................................................................................................... 11-1 11.2 MEASUREMENT SYSTEMS .................................................................................. 11-31 11.3 CONVERSION TABLE .......................................................................................... 11-33 Hydrogen Fuel Cell Engines and Related Technologies: Rev 0, December 2001 Hydrogen Fuel MODULE 11: GLOSSARY AND CONVERSIONS Cell Engines OBJECTIVES This module is for reference only. Hydrogen Fuel Cell Engines and Related Technologies: Rev 0, December 2001 PAGE 11-1 Hydrogen Fuel Cell Engines MODULE 11: GLOSSARY AND CONVERSIONS 11.1 Glossary This glossary covers words, phrases, and acronyms that are used with fuel cell engines and hydrogen fueled vehicles. Some words may have different meanings when used in other contexts. There are variations in the use of periods and capitalization for abbrevia- tions, acronyms and standard measures. The terms in this glossary are pre- sented without periods. ABNORMAL COMBUSTION – Combustion in which knock, pre-ignition, run- on or surface ignition occurs; combustion that does not proceed in the nor- mal way (where the flame front is initiated by the spark and proceeds throughout the combustion chamber smoothly and without detonation). ABSOLUTE PRESSURE – Pressure shown on the pressure gauge plus at- mospheric pressure (psia). At sea level atmospheric pressure is 14.7 psia. Use absolute pressure in compressor calculations and when using the ideal gas law. See also psi and psig. ABSOLUTE TEMPERATURE – Temperature scale with absolute zero as the zero of the scale. In standard, the absolute temperature is the temperature in ºF plus 460, or in metric it is the temperature in ºC plus 273. Absolute zero is referred to as Rankine or r, and in metric as Kelvin or K. -
Periodic Table of the Elements Notes
Periodic Table of the Elements Notes Arrangement of the known elements based on atomic number and chemical and physical properties. Divided into three basic categories: Metals (left side of the table) Nonmetals (right side of the table) Metalloids (touching the zig zag line) Basic Organization by: Atomic structure Atomic number Chemical and Physical Properties Uses of the Periodic Table Useful in predicting: chemical behavior of the elements trends properties of the elements Atomic Structure Review: Atoms are made of protons, electrons, and neutrons. Elements are atoms of only one type. Elements are identified by the atomic number (# of protons in nucleus). Energy Levels Review: Electrons are arranged in a region around the nucleus called an electron cloud. Energy levels are located within the cloud. At least 1 energy level and as many as 7 energy levels exist in atoms Energy Levels & Valence Electrons Energy levels hold a specific amount of electrons: 1st level = up to 2 2nd level = up to 8 3rd level = up to 8 (first 18 elements only) The electrons in the outermost level are called valence electrons. Determine reactivity - how elements will react with others to form compounds Outermost level does not usually fill completely with electrons Using the Table to Identify Valence Electrons Elements are grouped into vertical columns because they have similar properties. These are called groups or families. Groups are numbered 1-18. Group numbers can help you determine the number of valence electrons: Group 1 has 1 valence electron. Group 2 has 2 valence electrons. Groups 3–12 are transition metals and have 1 or 2 valence electrons. -
Electronegativity Seen As the Ground-State
Article Cite This: J. Am. Chem. Soc. 2019, 141, 342−351 pubs.acs.org/JACS Electronegativity Seen as the Ground-State Average Valence Electron Binding Energy † ‡ § Martin Rahm,*, Tao Zeng, and Roald Hoffmann † Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden ‡ Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada § Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States *S Supporting Information ABSTRACT: We introduce a new electronegativity scale for atoms, based consistently on ground-state energies of valence electrons. The scale is closely related to (yet different from) L. C. Allen’s, which is based on configuration energies. Using a combination of literature experimental values for ground-state energies and ab initio- calculated energies where experimental data are missing, we are able to provide electronegativities for elements 1−96. The values are slightly smaller than Allen’s original scale, but correlate well with Allen’s and others. Outliers in agreement with other scales are oxygen and fluorine, now somewhat less electronegative, but in better agreement with their chemistry with the noble gas elements. Group 11 and 12 electronegativities emerge as high, although Au less so than in other scales. Our scale also gives relatively high electronegativities for Mn, Co, Ni, Zn, Tc, Cd, Hg (affected by choice of valence state), and Gd. The new electronegativities provide hints for new alloy/compound design,