The Periodic Law

Mendeleev’s Periodic Table (1872) Dmitri Mendeleev 1st to publish an organized table of elements. Grouped elements by similar chemical properties. Arranged elements by increasing mass.

Henry Moseley (1913) Used X-Ray diffraction to determine how many protons are in an atom of an element. Grouped elements by similar chemical properties. Arranged elements by increasing atomic number.

Modern Russian Table

Chinese Periodic Table

Stowe Periodic Table

A Spiral Periodic Table

“Mayan” Periodic Table

Orbital filling table

Period The Periodic Table Group or Family Group or family Period

Properties of Metalloids Metalloids straddle the border between metals and nonmetals on the periodic table. Metals Nonmetals Metalloids

Periodic Table with Group Names Group or Family Noble Gases Halogens Transition Metals Alkali Metals Alkaline Earth Metals Boron Family Carbon Family Nitrogen Family Oxygen Family Inner Transition Metals

The Properties of a Group: the Alkali Metals Easily lose valence electron (Reducing agents) React violently with water Large hydration energy React with halogens to form salts

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 Copper, Cu, is a relatively soft metal, and a very good electrical conductor. Zinc, Zn, is more stable than potassium Mercury, Hg, is the only metal that exists as a liquid at room temperature

Properties of Nonmetals Carbon, the graphite in “pencil lead” is an example of a nonmetallic element. Nonmetals are generally poor conductors of heat and electricity Nonmetals tend to be brittle Unlike carbon, (a solid), many nonmetals tend to be gases at room temperature

Examples of Nonmetals Microspheres of phosphorus, P, a reactive nonmetal Sulfur, S, was once known as “brimstone” Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

Properties of Metalloids Metals Nonmetals Metalloids straddle the border between metals and nonmetals on the periodic table. Metalloids 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 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

Periodic means Repeating Pattern Periodic means Repeating Pattern. Do you see a repeating pattern for these 1st Ionization Energies?

1st, 2nd , and 3rd, Ionization energies of Magnesium Mg + 738 kJ  Mg+ + e- Mg+ + 1451 kJ  Mg2+ + e- Mg2+ + 7733 kJ  Mg3+ + e-