CH. 11 Periodic Table

First Elements known to man were Gold and Silver (Coins) and Copper, Tin, Iron (Tools and Weapons)

Dmitri Mendeleev Born: February 8, 1834 Where: Tobolsk, Siberia, Russia 1869 published first version of periodic table (atomic mass)

From Theory to Reality 1860’s, Mendeleev began looking at patterns among the properties of elements Created cards with the properties of elements

These cards included the density, appearance, atomic mass, melting point and information about the compounds formed by the elements He played “chemical solitaire” with them on his long train rides and would arrange and re-arrange them

He determined there was a repeating pattern of properties when the elements were arranged in order of increasing atomic mass He determined the properties were periodic, “happening at regular intervals”

Few Elements were missing, but he was able to predict their properties By 1886, all of the gaps of the Mendeleev’s Periodic Table had been filled

Gallium-31 (Ga) , Scandium-21 (Sc), and Germanium-32 (Ge), were discovered A few Element’s properties did not fit the pattern in Mendeleev’s Periodic Table. (Problem)

Henry Moseley Born: Nov. 23, 1887 Where: Weymouth, England Died: Aug. 10, 1915 (28 Years Old) (Killed in WWI)

In 1914, Moseley solved the mystery He was able to determine the number of protons in an atom. (atomic number) He rearranged the elements based on their atomic number rather than atomic mass

When arranged by atomic number, the elements fell into the proper place It was clear how many Elements still were undiscovered Helped find the Elements Technetium-43 (Tc), Promethium-61 (Pm), and Rhenium-75 (Re)

Periodic Law  states that the repeating chemical and physical properties of Elements change periodically with the Elements Atomic Number

How to Read Periodic Table Elements are classified according to their properties: -metal (92) -nonmetal (20) -metalloids (6) The # of electrons in the outer energy level helps determine which category an element belongs.

Here’s Your Sign!!!! -Atomic Mass -Name -Chemical symbol What does each Element Symbol mean? -Atomic Number -Atomic Mass -Name -Chemical symbol

Who gets to be cool and name the elements? An International Committee of Scientists (Nobel Prize Winners) Some are named after important scientists. (ex. Mendelevium) Some are named for geographical regions. (ex. Californium)

What are the letters for??? The symbol usually consists of 1 or 2 letters. First letter is always capitalized Second letter, if present, is always lower-case.

Some symbols come from the Latin meaning of the word Examples: Lead (Plumbum)= Pb Sodium (Antrim)= Na Gold (Aurum)= Au Mercury (Hydrargyrum) = Hg

-- Antimony (Stibium) = Sb -- Copper (Cuprum) = Cu -- Iron (Ferrum) = Fe -- Potassium (Kalium) = K -- Silver (Argentum) = Ag -- Tin (Stannum) = Sn

Today’s Periodic Table Period – row of Elements in the Periodic Table whose particles change gradually and predictably. Labeled 1-7

Horizontal (left to right) Rows or Periods Horizontal (left to right)

Group – contains Elements that have similar physical or chemical properties. 18 Columns

Vertical (top to bottom) Columns or Groups Vertical (top to bottom)

Zones of Periodic Table 1) Representative Element Elements in Groups 1 and 2, and 13 through 18 in the periodic table that includes metals, metalloids, and nonmetals.

2) Transition Elements  Elements in Groups 3 through 12 in the periodic table, all of which are metals.

Metals  Element that has: Luster – ability to reflect light Malleable – ability to be pressed or pounded into thin sheets Ductile – ability to be made into wire

Good Conductor of Heat and Electricity All solids except Mercury High melting points

Gas or Brittle Solid at room temperature Non-Metals Element that is: Gas or Brittle Solid at room temperature Poor Conductor of Heat and Electricity No Luster

Not Malleable Not Ductile Bromine- is the only Non-Metal that is a liquid

Metalloids Element that shares some properties with both Metals and Nonmetals Semiconductor Element that does not conduct electricity as well as a metal but conducts it better than a nonmetal.

b. Are poor conductors of electricity at low temperatures b. Are poor conductors of electricity at low temperatures. If you increase its temperature, it becomes a good conductor.  Electrical Devices

Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te)

Representative Elements Group 1: Alkali Metals --Shiny Solids --Low Densities --Low Melting Points --Most Chemically Active Group (Most Important)

--Li, Na, K, Rb, Cs, Fr *As move from top to bottom Elements increase in reactivity or tendency to combine with other substances.

Group 2: Alkaline Earth Metals --Dense and Hard --Higher Melting Point --Chemically Active (less reactive than Group 1)

Transition Elements --All are Metals, Groups 3 - 12 Iron Triad —three elements (Iron, Cobalt, and Nickel) have magnetic properties.

Inner Transition Elements 1) Lanthanides 2) Actinides

Lanthanides Not Radioactive Soft Metals that can be cut with a butter knife Shiny and Reactive

Actinides Radioactive and Unstable Majority are Synthetic Elements (Made in Laboratory)

Group 13 = Boron Group Group 14 = Carbon Group Group 15 = Nitrogen Group Group 16 = Oxygen Group

Group 17: Halogen Group --Combine with metals to form salts --NaCl (Sodium Chloride)

Group 18: Noble Gases --Do not react chemically with other Elements. They are Inert (inactive).

Reactivity of Elements Metals: (Left Side of Periodic Table) 1. If Elements are in same Period then the most reactive is the Element closer to Group 1. 2. If Elements are in same Group then the Element with highest Atomic Number is the most reactive because of higher numbers of Protons, Neutrons, and Electrons.

Reactivity of Elements Which Element is the most Reactive? -- K, Ca, Sc, Ti, V = __________ -- Li, Na, K, Rb, Cs = __________

Reactivity of Elements Non-Metals: (Right Side of Periodic Table) 1. If Elements are in same Period then the most reactive is the Element closer to Group 17. Group 18 is never Reactive. 2. If Elements are in same Group then the Element with highest Atomic Number is the most reactive because of higher number of Protons, Neutrons, and Electrons.

Reactivity of Elements Which Element is the most Reactive? -- C, N, O, F = __________ -- F, Cl, Br, I = __________

Hydrogen Group The properties of Hydrogen do not match the properties of any single group, but they do share the property of one Valance Electron just like Elements in Group 1 Are classified as a Non-Metal because it shares more properties with Non-Metals than Metals