The Periodic Table

Father of the Periodic Table In the early 1800s several scientists tried to organize the elements In 1869 Dmitri Mendeleev was able to arrange elements by their chemical properties, using rows and columns We call this table periodic because it shows a periodic, repeating pattern of properties of the elements.

Reading the Periodic Table Atomic number Atomic mass Element nameChemical symbol13Al Aluminum

Pop Quiz Question #1 Who is Dmitri Mendeleev? A. He discovered the most elements. He discovered the most elements. B. He created the periodic table He created the periodic table C. He named the periodic table He named the periodic table D. He discovered Mendelevium (atomic number 101) He discovered Mendelevium (atomic number 101)

Groups and Periods Elements in a vertical column have similar physical and chemical properties Vertical columns are called groups or families The chemical properties of elements in horizontal rows show a progression Horizontal rows are called periods

Pop Quiz Question #2 Which way is a group organized? A. A group is a row. A group is a row. B. A group is a column. A group is a column.

Trends on the Periodic Table Sizes of the atoms decrease as we move from left to right across a period This is due to the increasing number of protons in the nucleus, so the electrical attraction between the nucleus and the orbiting electrons gets stronger and pulls the electrons closer to the nucleus

Atom size decreases Atom size increases

Pop Quiz Question #5 How does the size of atoms change as you go from left to right across the periodic table? A. Atoms get larger moving left to right Atoms get larger moving left to right B. Atoms get larger moving right to left Atoms get larger moving right to left C. Atoms get larger moving down a group Atoms get larger moving down a group D. Atoms get larger moving up a group Atoms get larger moving up a group

Three Main Regions Metals – on the left Metalloids – stair steps Nonmetals – on the right

Characteristics of Most Metals Shiny Malleable and ductile (can be shaped into sheets and wires) Good conductors of heat and electricity Solid at room temperature (except Mercury)

Alkali Metals Soft, silvery colored metals Very reactive!!!

Alkali Metals reacting with water: Li (Lithium) Na (Sodium) K (Potassium) Rb (Rubidium) Cs (Cesium) What would you expect from Francium?!?!

Alkaline Earth Metals Silvery-White Metals (shiny) Fairly reactive Many are found in rocks in the earth’s crust

Transition Metals Malleable Conductors of heat/ electricity &

Pop Quiz Question #6 What are the three main parts to the periodic table? A. Solids, liquids, gases Solids, liquids, gases B. Protons, neutrons, electrons Protons, neutrons, electrons C. Metals, nonmetals, metalloids Metals, nonmetals, metalloids

How many things can you think of that have Transition Metals in them?

Metalloids lie on either side of these “stair steps” They share properties with both metals and non-metals Si (Silicon) and Ge (Germanium) are very important “semi-conductors”

What are semiconductors used in?

Nonmetals Brittle Do not conduct electricity

Most are Poisonous Fairly reactive Halogens

Chlorine Gas was used as a chemical weapon during World War I. It was used by the Nazis in World War II. Halogen Uses

Unreactive Gases at room temperature Noble Gases

Neon Signs with Noble Gases NeonArgonHelium KryptonXenon

Actinide Series Rare Earth metals Lanthanide Series Radioactive metals

The Elements Song Sung by Tom Lehrer, from the 1959 periodic table Sung by Tom Lehrer, from the 1959 periodic table