The Periodic Table

Table of ContentsLecture/Lab/Activity Date Pg#

14. The History of Atomic Models 9/14/10 3115. Structure of the Atom 9/15/10 3516. Isotopes 9/16/10 3717. Beanium Lab 9/17/10 18. Electron Probability Lab 9/20/10 919. Electron Configuration 9/21/10 4120. Orbital Diagrams 9/22/10 4321. Electron Config Practice 9/23/10 4522. The Periodic Table 9/24/10 47

Objective:The student will review the historical development of the periodic table by creating a graphic organizer to compare how elements were arranged and their different properties.

Agenda:The Periodic Table– Lecture

Mendeleev’s Periodic Table-1869Mendeleev’s Periodic Table-1869

Dmitri Mendeleev•Organized by increasing atomic mass

•Elements with similar properties are grouped together

•Predicted properties of undiscovered elements

Henry Mosely (1913, British)

• Organized elements according to atomic number

• Resolved discrepancies in Mendeleev’s arrangements

Periods and Groups

• Periods or Rows– Horizontal Rows– Numbered 1-7– Indicate Energy Level (n)

• Groups or Families• groups contain elements with similar properties in vertical

columns.

Group Numbers

• use the letter A for the representative elements (1A to 8A) and the letter B for the transition elements.

• also use numbers 1-18 to the columns from left to right

The Periodic TableThe Periodic Table

Period

Group or family

PeriodGroup or Family

Roman Numeral = Valence electrons

Periods and Groups

Properties of Metals Metals are good conductors of heat and electricity

Metals are malleable

Metals are ductile

Metals have high tensile strength

Metals have luster

Examples of Metals

Potassium, K reacts with water and must be stored in kerosene

Zinc, Zn, is more stable than potassium

Copper, Cu, is a relatively soft metal, and a very good electrical conductor.

Mercury, Hg, is the only metal that exists as a liquid at room temperature

•   Easily lose valence electron (Reducing agents) •   React violently with water •   Large hydration energy •React with halogens to form • salts •Most Reactive Metal because of their readiness to form new substances•Silvery solids with low density and low melting points

The Properties of a Group I: the Alkali Metals

The Properties of a Group II:

the Alkaline Earth Metals

•  Alkaline earth metals are denser and harder and have a higher melting point than alkali metals in the same period•Alkaline earth metals are reactive but not as reactive as the Alkali Metals

Properties of Nonmetals

Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. Nonmetals are poor conductors of heat and electricity Nonmetals tend to be brittle Many nonmetals are gases at room temperature

Examples of NonmetalsExamples of Nonmetals

Sulfur, S, was once known as “brimstone”

Microspheres of phosphorus, P, a reactive nonmetal

Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

Group 17, Halogens

• Halogens means ‘salt-former’

• Form Salts with Alkali Metal Group

• Reactivity: Fluorine (highest) and decreases going down group Iodine (lowest)

• F and Cl are gases• Br is a liquid• I is a solid

Group 18, Noble Gases

• Rarely react with other elements

• Low reactivity• Have a full outer shell

Groups 13 - 16

• Group 13 – The Boron Family; all metals except Boron

• Group 14 – The Carbon Family; found in all living organisms

• Group 15 – The Nitrogen Family; health, environment

• Group 16 – The Oxygen Family; first two elements essential for life

Properties of MetalloidsProperties of Metalloids

Metalloids straddle the border between metals and nonmetals on the periodic table.

They have properties of both metals and nonmetals. Metalloids are more brittle than metals, less brittle than most nonmetallic solids Metalloids are semiconductors of electricity Some metalloids possess metallic luster

Silicon, Si – A MetalloidSilicon, Si – A Metalloid

Silicon has metallic luster Silicon is brittle like a nonmetal Silicon is a semiconductor of electricity

Other metalloids include:

Boron, B Germanium, Ge Arsenic, As Antimony, Sb Tellurium, Te