The Periodic Table Ag. Physical Science Ms. Weigel

Predicting Properties Goal: Identify the pattern Ms. Weigel used to create your seating chart. Procedure: 1.Draw a seating chart for the new classroom arrangement. Write the name of each of your classmates in the place on the chart that corresponds to his or her seat. 2.Write information about yourself, such as your name, date of birth, hair color and height in the space that represents you on the chart 3.Gather the same information about the people near you and write it in the spaces on the chart.

Predicting Properties Analyze: 1.From the information you gathered, identify a pattern that could explain the order of people in the chart. 2.Test your pattern by gathering information. IF the new information does not support your pater, collect more information and identify another patter. 3.If your teacher left a seat open for a student, what information could you predict about the studetn using a pattern as a tool?

SEC. 1: ARRANGING THE ELEMENTS Elements are arranged on the periodic table according to their atomic number and their chemical properties

Suppose you are at a book store, how are books arranged? If there was not a pattern how would you find anything? Scientists in the early 1860’s had a similar problem. At that time scientists new about 60 elements but no one had organized them.

I. Discovering a pattern 1.Dmitri Mendeleev, a Russian chemist, discover a pattern to the elements in First, he wrote the names and properties on cards and played chemical solitaire. 3.He eventually arranged the elements in order of increasing atomic mass.

A. Periodic Properties of the Elements 1.Periodic means “happening at regular intervals” – Days of the week are periodic 2.Mendeleev pattern repeated every seven elements 3.His table became known as the periodic table of the elements.

B. Predicting Properties of Missing Elements 1.Mendeleev’s first attempt 2. He used the pattern he found to predict their properties 3. By 1886 all the gaps had been filled, his predictions were right. GermaniumMendeleev 1869Actual Properties Atomic Mass Density5.5 g/cm35.3 g/cm3 AppearanceDark Gray MetalGray Metal Melting PointHigh Melting Point937 Degree C

II. Changing the Arrangement 1.A few properties did not fit the pattern 2.In 1914, Henry Moseley, a British scientists, determined the number of protons- the atomic number- in an atom. 3.All elements fit the patter in Mendeleev’s period table when they were arranged by atomic number.

III. The Periodic Table and Classes of Elements 1.Elements are classified according to their properties as metals, nonmetals and metalloids. 2.Regions of the periodic table correspond to classes of elements

A. Metals 1.Most elements are metals 2.Metals are found to the left of the zigzag line on the periodic table 3.Atoms of most metals have few electrons in their outer energy level. 4.Most metals are solid at room temp. – Except Mercury.

B. Nonmetals 1.Nonmetals are found to the right of the zigzag line on the periodic table. 2.Atoms of most nonmetals have an almost complete set of electrons in their outer level (8). 3.More than half of the nonmetals are gases at room temp.

C. Metalloids 1.Metalloids, also called semimetals, are the elements that border the zigzag line on the periodic table. 2.Atoms of metalloids have about half of a complete set of electrons in their outer shell. 3.Metalloids have some properties of metals and some properties of nonmetals. Ex. Boron= almost as hard as diamond, but also very brittle. Good conductor of electric current.

Color the Periodic Table Metals=Blue Metalloids= GreenNonmetals=Yellow

IV. Decoding the Periodic Table 1.The periodic table may seem to be in code. 2.In a way, it is. Symbols and numbers can help you find your way around.

A. Chemical Symbols 1.Each square includes an elements name, chemical symbol, atomic number and atomic mass. 2.A scientist who discovers an element can name it. – Named after the person, or a place 3.For most elements, the symbol is made of two letters, the first is always capital with the second lower case- quick way to identify elements

B. Periods 1.Each horizontal row of elements (from left to right) on the table is called a period. 2.The physical and chemical properties of elements in a row follow a repeating pattern across the table.

C. Groups 1.Each vertical column (from top to bottom)on the table is called a group. 2.Elements in the same group often have similar chemical and physical properties. 3.For this reason they are also called a family

D. Atomic Number 1.The periodic law states that the repeating chemical and physical properties of elements change periodically with the elements atomic numbers. 2.The atomic number = the number of protons 3.All atoms of a given element have the same number of protons in the nucleus

TedED time!! mgU&spfreload=10 mgU&spfreload= znAg7VE&spfreload= znAg7VE&spfreload=10

Review Page 201 #1-6

SEC 2 GROUPING THE ELEMENTS Elements within each group, or column, on the periodic table have similar properties

Think about your family members…. How do you compare in looks? The elements in a family or group in the periodic table often-but not always- have similar properties Atoms will often take, give or share electrons with other atoms in order to have a complete set in their out energy level (8 e)

Group 1 Alkali Metal Group contains: Metals Electrons in the out level: 1 Reactivity: very reactive Shared properties: softness, color of silver, shininess

Group 2: Alkaline- Earth Metals Group contains: Metals Electrons in the outer level: 2- easier to give away 2 than gain 6 Reactivity: very reactive but less than alkali metals Shared properties: color silver, high density

Groups 3-12: Transition Metals

Groups 3-12 Transition Metals Groups contain: Metals Electrons in the outer level: 1 or 2 Reactivity: less reactive than earth metals Shared properties: shininess, good conductivity of thermal energy and electric current, higher melting point than groups 1 & 2 (except for Mercury)

Group 13: Boron Group Group Contains: one metalloid and five metals Electrons in the outer level:3 Reactivity: reactive Shared Properties: solids at room temp

Group 14: Carbon Group Group Contains: one nonmetal, two metalloids and three metals Electrons in the outer level: 4 Reactivity: varies among the elements Shared Properties: solids at room temp.

Group 15: Nitrogen Group Group Contains: two nonmetals, two metalloids and two metals Electrons in the outer level: 5 Reactivity: varies among the elements Shared Properties: solids at room temp except for nitrogen

Group 16: Oxygen Group Group Contains: three nonmetals, one metalloid and on metal Electrons in the outer level:6 Reactivity: reactive Shared Properties: solids at room temp except for oxygen

Group 17: Halogens Group Contains: nonmetals Electrons in the outer level: 7 Reactivity: very reactive Shared Properties: poor conductors of electric current, violent reactions with alkali metals to form salts, never in uncombined form in nature.

Group 18: Nobel Gases Group Contains: nonmetals Electrons in the outer level: 8 (except helium, which has two) Reactivity: Unreactive Shared Properties: colorless, odorless gases at room temp

Hydrogen Electrons in the outer level:1 Reactivity: Reactive Properties: colorless, odorless gas at room temperature, explosive reactions with oxygen

Review Page 209 #1-8 & 10