Dmitri Mendeleev: Father of the Table HOW HIS WORKED… SOME PROBLEMS… He had to break his own pattern of increasing atomic weight to keep similar reacting elements together.

The Current Periodic Table Mendeleev wasn’t too far off. Now the elements are put in rows by: The horizontal rows are called: The vertical columns are called:

Here’s Where the Periodic Table Gets Useful!! Elements in the same group have: Why?? It’s related to their electrons, specifically all atoms in a group have the same number of valence electrons. They will form:

_____________ Metals 1st column on the periodic table (Group 1) including hydrogen. Soft enough to cut with a butter knife

_______________________ Metals Second column on the periodic table. (Group 2) Reactive metals that: Several of these elements are important mineral nutrients. Which ones?

________________ Metals Elements in groups 3-12 Less reactive harder metals Includes metals:

_______ Family Group 13 ________ Family Group 14 Carbon is the basis for an entire branch of chemistry, used in steel production, graphite, and carbon fiber. Silicon is an important semiconductor used in computer applications. Tin used in soldering, joining metals. Boron is the only metalloid in the group and has many different properties – used in fiberglass and ceramics. Plant cells use Boron to strengthen plant walls. Aluminum metal:

______ Family Group 15 _____ Family Group 16 Nitrogen makes up over ¾ of the air we breath. Also: Phosphorus is also important in the body and used in fertilizers. Elemental Arsenic can be toxic if ingested. Elements in group 16 Oxygen is necessary for respiration and photosynthesis. Many things that stink, contain:

___________ Group 17 Elements in group 17 Very Always found combined with other element in nature . Used as disinfectants and to strengthen teeth.

The ___________ Gases Elements in group 18 Very Used in lighted “neon” signs Used in blimps to fix the Hindenberg problem. Have a full valence shell.

Metalloids A collection of elements that fall: Because these elements are between metals and nonmetals, they are described as having:

__________________ _____________ Contains 14 different elements Are used as catalyst in petroleum products, as well as lasers, magnets, and motion picture projectors. Many scientific and industrials uses. _____________ All of these elements are radioactive. Uranium and Plutonium used in Nuclear power plants and bombs They react with water and acids to produce Hydrogen. Many of these were created by scientist.