NOTES. The Periodic Table

Size: px

Start display at page:

Download "NOTES. The Periodic Table"

Sara Owens
7 years ago
Views:

1 NOTES COMPLETE The Periodic Table Ch. 6 What elements do you already know about that we use everyday AND are, for the most part, known by just about everybody? Silver, Gold, and Copper have been known for thousands of years. By 1700, only 13 elements had been identified. Between 1765 and 1775 ( one decade ), only 5 new elements were identified, including the colorless gases. Hydrogen, Nitrogen, and Oxygen Early chemists were trying to figure out if there was a limited number of elements. 2 1

2 EARLY ATTEMPTS AT CLASSIFICATION TRIADS - a set of three elements with similar properties Example: Chlorine, Bromine, and Iodine 1. They each reacted easily with metals 2. The average of atomic mass of Chlorine and Iodine together was almost exactly the same as the average atomic mass of Bromine J.W. DOBEREINER ( ) - proposed the Triad System 3 DMITRI MENDELEEV ( ) - Russian chemist and teacher who first published major periodic table in His periodic table was based on increasing atomic mass and consisted of 60 elements. Mendeleev s table had discrepancies: 1. It had holes between known elements 2. Elements with similar properties were not always where they should be 4 2

3 5 HENRY MOSELEY ( ) - British physicist who published the modern periodic table in 1913 Moseley s periodic table was based on the increasing atomic number of each element. Moseley s Modern Periodic Table 6 3

4 Periodic Families 7 Periodic Periods 8 4

5 There are 7 rows ( periods ) or ( series ) Row / Period 1 has 2 elements Row / Period 2 has 8 elements Row / Period 3 has 8 elements Row / Period 4 has 18 elements Row / Period 5 has 18 elements Row / Period 6 has 32 elements Row / Period 7 has 32 elements 9 PERIODIC LAW - when atoms are arranged in order of increasing atomic number, there is a periodic repetition ( ) pattern in their chemical and physical properties. Elements that have similar chemical and physical properties end up in the. same column ( families ) ( groups ) 10 5

6 11 There are three classes of elements: Metals, Non-Metals, and Metalloids Across a period, the properties of elements become less metallic and more nonmetallic 12 6

8 METALS - make up about 80% of all elements 1. Good conductors of heat and electricity 2. High luster or sheen ( shiny ) because they reflect light 3. Solid at room temperature 4. Ductile drawn into wires 5. Malleable hammered or pressed into sheets

9 17 NONMETALS - have properties that are opposite of metals 1. A greater variation in physical properties than metals 2. Most are gases at room temperature 3. A few are solids, some are liquids 4. Poor conductors 5. Brittle will shatter if hit with a hammer 6. NOT ductile or malleable 18 9

10 METALLOIDS - elements along the stair-stepline 19 METALLOIDS 1. Have properties similar to metals and nonmetals 2. One condition = like a metal 3. Another condition = like a nonmetal Example: Pure Silicon = poor conductor of electricity Add a small amount of Boron = mixture is a good conductor of electricity, making it good to make computer chips 20 10

12 The periodic table is a very useful tool in chemistry. PERIODIC TABLE - usually displays the symbols and names of the elements, along with information about the structure of their atoms 23 ALKALI METALS - the family name of the elements found in column 1A; these elements are metals ALKALINE EARTH METALS - the family name of the elements found in column 2A; these elements are metals Example: Wood ashes are rich in the elements Sodium and Potassium HALOGENS - the family name of the elements found in column 7A; these elements are nonmetals and also known as the salt formers 24 12

13 25 NOBLE GASES - elements found in column 8A; includes Helium, Neon, Argon, Krypton, Xenon, Radon, and Unonoctium ( unknown ) 26 13

14 REPRESENTATIVE ELEMENTS - elements in groups 1A through 7A; they display a wide range of. physical and chemical properties Some are, metals some are, nonmetals and some are. metalloids Most of them are, solids but a few are, gases at room temperature and one, Bromine is. liquid at room temperature

15 MAIN GROUP METALS - the A groups; the metallic elements in groups 1A through 7A TRANSITION METALS - the B group elements that separate groups 1A and 2A from groups 3A through 7A; usually displayed in the main part of the table, such as Copper, Silver, Gold, and Iron INNER TRANSITION METALS - the elements that appear below the main body of the table, such as Uranium, Plutonium, and Einsteinium

16 ATOMIC RADIUS - one half the distance between the nuclei of two atoms of the same element when the atom are joined PICOMETER - 1 trillionth ( 1 / 1,000,000,000,000 ) of a meter 31 Left to right = atomic radius decreases ( gets smaller ) Top to bottom = atomic radius increases ( gets larger ) 32 16

17 33 17

Class Notes Standards Addressed: 8.3.11

Name: Period #: Class Notes Standards Addressed: 8.3.11 History of the Periodic Table: Demitri Mendeleev = Russian chemist who discovered a pattern to the in 1869. o How did he discovery a pattern to the