Periodic Table?

What happens to the number of electron shells as you go across the periodic table? Down the peridic table? What happens to the number of electrons in the outside shell as you go across the periodic table? Down the periodic table?

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What is the periodic table used for in biology and physics? What is the table used for finding in the subject?

I need to know how is the periodic table is used for in Biology and Physics? What information can you gather using the table and use it in biology/physics? Also, what industries use the periodic table...some links to information on the industries would help.

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What is the answer to this periodic table problem?

Indicate the location on the periodic table of the following atoms, using the choices: top-left, top-right, bottom-left, bottom- right. Where is the smallest atom? How can it be top left? Helium is on top-right!

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