Introduction to the Periodic Table

Chapter 3

Objectives 3.1

• Outline the steps in the historic development of the periodic table

• Predict similarities in properties of the elements by using the periodic table.

Key Terms 3.1

• Group (columns)

• Period (rows)

• Periodic law (atoms arranged by increasing atomic number)

Historical Perspective

• Mendeleev credited with being the first to organize the periodic table (same guy who did the punnett square)– Really smart guy, left blanks in where he

thought (knew) that another element would be discovered and predicted the properties of the element

• Organized by mass– Modern organized by atomic number

Development of Periodic Table

Mendeleev, for instance, predicted the discovery of germanium (which he called eka-silicon) as an element with an atomic weight between that of zinc and arsenic, but with chemical properties similar to those of silicon.

Historical Perspective

• The periodic table is organized by groups.

• Each group has similar properties (vertical columns)– Oxygen is similar to Sulfur is similar to

Selenium

• This is all because of having similar valence structures (which are again the electrons which do the interacting)

Mendeleev’s table

Development of Periodic Table

• Elements in the same group generally have similar chemical properties.

• Properties are not identical, however.

Development of Periodic Table

Dmitri Mendeleev and Lothar Meyer independently came to the same conclusion about how elements should be grouped.

End 3.1 Notes. Can you?

• Predict which elements share similar properties to Oxygen (O)?

• Summarize how the periodic table is organized?

• Compare how Mendeleev organized his table to the modern table?

Chapter 3.2 Objectives

• Relate an element's valence electron structure to its position in the periodic table

• Compare and contrast properties of metals, non-metals, and metalloids.

• Use the periodic table to identify elements as metals, non-metals, and metalloids

• Learn about 4 special families in the periodic table with associated properties

Key Terms 3.2

• Metal• Nonmetal• Metalloid• Semiconductor

– Conductor– Insulator

• Transition Elements• Lanthanide• Actinide• Alkali Metals• Alkaline Earth Metals• Halogens• Noble Gases

Periodic TablePeriodic Table

Metals

Properties of Metals

• Luster

• Conductors (Heat/Electrons)

• Malleable

• Ductile

• Most are solid at room temperature

• Loosely held valence electrons

Nonmetals

Properties of Nonmetals

• Insulators

• Brittle

• Dull

• Many are gases at room temperature

• Tightly held valence electrons

Semi-metals or Metalloids

Metalloids

• Have properties of both– Instead of thinking an element is purely a

metal or only a nonmetal, think of the periodic table as a spectrum.

– Lower left is the best metal, as you move towards the top right, you lose your metal properties and become more of a nonmetal

– Metalloids are in the middle– What metal and nonmetal properties does

Gold have?

Properties of Metal, Nonmetals,and Metalloids

Alkali Metals

One Word: First Column

Alkaline Earth Metals

Two Words: Second Column

Halogens (Name: Salt Maker)

Noble Gases (Inert Gases)

Lanthanide and Actinide

Transition Metals

Random info on following slides

Element Sym # of Atoms Element Sym # of Atoms Element Sym # of Atoms

Hydrogen H 4.22 x 1027 Rubidium Rb 2.2 x 1021 Zirconium Zr 2 x 1019

Oxygen O 1.61 x 1027 Strontium Sr 2.2 x 1021 Cobalt Co 2 x 1019

Carbon C 8.03 x 1026 Bromine Br 2 x 1021 Cesium Cs 7 x 1018

Nitrogen N 3.9 x 1025 Aluminum Al 1 x 1021 Mercury Hg 6 x 1018

Calcium Ca 1.6 x 1025 Copper Cu 7 x 1020 Arsenic As 6 x 1018

Phosphorus P 9.6 x 1024 Lead Pb 3 x 1020 Chromium Cr 6 x 1018

Sulfur S 2.6 x 1024 Cadmium Cd 3 x 1020 Molybdenum Mo 3 x 1018

Sodium Na 2.5 x 1024 Boron B 2 x 1020 Selenium Se 3 x 1018

Potassium K 2.2 x 1024 Manganese Mn 1 x 1020 Beryllium Be 3 x 1018

Chlorine Cl 1.6 x 1024 Nickel Ni 1 x 1020 Vanadium V 8 x 1017

Magnesium Mg 4.7 x 1023 Lithium Li 1 x 1020 Uranium U 2 x 1017

Silicon Si 3.9 x 1023 Barium Ba 8 x 1019 Radium Ra 8 x 1010

Fluorine F 8.3 x 1022 I odine I 5 x 1019

I ron Fe 4.5 x 1022 Tin Sn 4 x 1019

Zinc Zn 2.1 x 1022 Gold Au 2 x 1019 TOTAL 6.71 x 1027

Human Body Chemistry

• Table 3-1. Estimated Atomic Compositionof the Lean 70-kg Male Human Body(compiled & adapted from [749, 751-752, 817])

• The human body consists of ~7 x 10^27 atoms arranged in a highly aperiodic physical structure. Although 41 chemical elements are commonly found in the body's construction (Table 3-1), CHON comprises 99% of its atoms. Fully 87% of human body atoms are either hydrogen or oxygen.

Human Body Chemistry

• Calcium: Bones, teeth; essential for blood clotting and muscle contraction

• Phosphorus: bones, teeth; component of nucleic acids (DNA)

• Potassium: Present as K+ in all body fluids, essential for nerve action

• Sulfur: Component of proteins, essential for blood clotting

Human Body Chemistry

• Chlorine: Present as Cl- in all body fluids, important to maintaining salt balance

• Sodium: Present as Na+ in all body fluids, essential for muscle and nerve action

• Magnesium: In bones and teeth, essential for muscle action

• CHNO make up over 99% of our body