A Dream Mendeleev - most well known for being the creator of the periodic table and predicting elements that were not yet discovered. Rumor has it that Mendeleev had been trying to figure out the periodic table for many weeks but couldn’t get all the elements onto one table. Exhausted, he laid down for a nap. While sleeping, he dreamed of the periodic table all laid out including known and elements that were then unknown. He woke up and wrote it down. 1

Mendeleev’s Periodic Table Only 63 elements at that time

Rows on the Periodic Table Elements on the periodic table can be put into rows called periods based on their atomic number, atomic mass, and reactivity. Generally as you move from left to right across a period elements are less reactive. On the left is an reactive solid – at right is a non- reactive gas

Groups on the Periodic Table Elements on the periodic table can be put into groups called based on their chemical properties. Each group has a specific name to differentiate it from the other families in the periodic table. Elements in each group react differently with other elements.

ALKALI METALS Hydrogen is not a member, it is a non-metal Soft and silvery metals Very reactive, esp. with water One valence electron

ALKALINE EARTH METALS White and malleable Reactive, but less than Alkali metals 2 Valence electrons

TRANSITION METALS Groups in the middle Good conductors of heat and electricity. Some are used for jewelry. Can bond with many elements in a variety of shapes.

METALLIODS Chemically behave as non-metals Conductive like metals Semi-conductors Used in electronics and computer components

NONMETALS Lack-properties of metals Not conductive Not ductile Not malleable

Noble Gases Exist as gases Non-metals Not reactive with other elements Full valence electron orbitals

Rare Earth Metals Some are Radioactive The rare earths are silver, silvery-white, or gray metals. Conduct electricity