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.

Mendeleev’s Periodic Table Only 63 elements at that time

Rows on the Periodic TableElements 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 reactivesolid – at right is a non-reactive gas

Groups on the Periodic TableElements 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 metalsVery reactive, esp. with

waterOne valence electron

ALKALINE EARTH METALSWhite and

malleableReactive, but

less than Alkali metals

2 Valence electrons

TRANSITION METALSGroups in the

middle

Good conductors of heat and electricity.

Some are used for jewelry.

Can bond with many elements in a variety of shapes.

METALLIODSChemically

behave as non-metals

Conductive like metals

Semi-conductorsUsed in

electronics and computer components

NONMETALSLack-properties

of metalsNot conductiveNot ductileNot malleable

Noble GasesExist as

gasesNon-metalsNot 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