How Are Electrons Arranged in an Atom

Technical Reading Enduring Understanding As matter and energy cycle through systems, atoms and molecules are transformed and recombined in different ways. It’s Elemental Concepts Important to Know and Understand energy stored and released through chemical bonds EQ: How does a system maintain balance? Broad Brush Knowledge properties of matter

Targeted Skills Core Objectives  Communication 4. Identify the structure and properties of atoms and elements.  Determine purpose 5. Determine properties used to position an element within the  gather information periodic table.  Analyze words 6. Identify the transformations of atoms, molecules, and energy  identify context clues that occur within cycles in the environment.

Purpose Gather information and develop technical reading skills.

Expert Information: One hundred sixteen different kinds of atoms have been identified. Every bit of matter, living or non-living, is made up of one or more of these 116 types of atoms. An element is a substance that contains only one type of atom. A chart of the elements called the periodic table is a common feature found in many science labs. The atoms of an element are virtually identical. In this diagram, the atoms of the element gold (Au) are shown as small circles. One atom of this material would have the properties of gold that the entire piece has. On the other hand, the atoms that make up one element are unlike the atoms that make up any other element. All matter on the Earth is composed of elements. Most elements are solids, such as gold, silver, and copper. Some elements, like oxygen and neon, are gasses, and only mercury and bromine are liquids at room temperature. Only 92 elements exist outside of chemistry labs. Scientists have made very small amounts of the remaining 24 elements. By bombarding atoms with particles, scientists create new elements, but these only exist a short time, often only seconds! Since new elements can be created, the periodic table is continually expanding Names of elements are written as symbols. The symbols for elements always begin with a capital letter. Symbols are not abbreviations, so periods are not used after the symbol unless it ends a sentence. In some circumstances, the symbol consists of two or three letters. When there is more than one letter, the letters following the first letter are written in lower case. For example, Au is the symbol for gold. These same symbols are used in all countries. The names and symbols of the elements used on the periodic table have several different origins. Some of the symbols are the first letter of the element’s name such as C for carbon. If the first letter of the element’s name has been used, another letter from the name is added. An example would be Co for cobalt. Most of the names, and therefore the symbols, of the elements are from Latin and Greek words. Cu is the symbol for copper and is derived from the Latin word cyprium. Other elements are named for numbers (unnilquadium), places (francium) and people (radium). Sometimes, the name and symbol have different origins. The element tungsten was named for the Swedish words tungs and ten which means heavy stone. But the symbol, W, is from the German name wolfram. Just think, if you become a famous scientist, your initials may live forever on the periodic table!

© 2006 Plano ISD, Plano, TX/Klein ISD 2007 1 1 2 H He Hydrogen Helium 1 4 3 4 5 6 7 8 9 10 Li Be B C N O F Ne Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon 7 9 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar Sodium Magnesium Aluminum Silicon Phosphorus Sulfur Chlorine Argon 23 24 27 28 31 32 35 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Potassium Calcium Scandium Titanium Vandium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton 39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

Use the partial periodic table to identify the symbols for the following elements. Write the symbol beside the name.

1. oxygen 4. calcium 7. iron (ferrum) 2. carbon 5. helium 8. potassium (kalium) 3. hydrogen 6. aluminum 9. lithium (lithos)

Analysis

10. What methods are used to determine the names of many elements?

11. How many elements occur in nature?

12. What is matter called that has only one kind of atom?

13. In what phase or state do most elements occur naturally?

14. Why do you think the same element names and symbols are used all over the world?

15. Since the elements that are created in labs only exist a short period of time, why do you think scientists spend time and money performing these experiments?