The Periodic TableThe Periodic Table

Arrangement of elements based on Arrangement of elements based on propertiesproperties– Dmitri MendeleevDmitri Mendeleev

Mid 1800’sMid 1800’s Arranged elements by increasing atomic massArranged elements by increasing atomic mass Left blanks for undiscovered elementsLeft blanks for undiscovered elements

– Henry MoseleyHenry Moseley 19131913 Arranged by atomic numberArranged by atomic number

MendeleevMendeleevSing along with the chorus!Sing along with the chorus!

Who told the elements where to go?Who told the elements where to go?Mendeleev!Mendeleev!Who put them into columns and in rows?Who put them into columns and in rows?Mendeleev!Mendeleev!Who was ready, who was able to make a Who was ready, who was able to make a

periodic table, periodic table, Who was that chemist? Mendeleev!Who was that chemist? Mendeleev!

PeriodsPeriods- Horizontal rows- Horizontal rows– Just numberedJust numbered– Gives rise to the Gives rise to the Periodic LawPeriodic Law – that when the – that when the

elements are arranged in increasing atomic elements are arranged in increasing atomic number there are properties that repeat number there are properties that repeat themselves.themselves.

Groups or FamiliesGroups or Families – Vertical columns – Vertical columns– Arranged by similar propertiesArranged by similar properties– Representative ElementsRepresentative Elements = Groups 1A to 7A = Groups 1A to 7A

and 0 (tall columns)and 0 (tall columns)

MetalsMetals – Ductile, malleable, luster and high – Ductile, malleable, luster and high conductivityconductivity– Alkali MetalsAlkali Metals – Group 1A – Group 1A– Alkali Earth MetalsAlkali Earth Metals – Group 2A – Group 2A– Transition MetalsTransition Metals – Groups 3B to 2B (Short – Groups 3B to 2B (Short

Columns)Columns)– Inner Transition ElementsInner Transition Elements – Two Rows that are – Two Rows that are

separate. (Also called the rare Earth elements)separate. (Also called the rare Earth elements)– 80% of all elements are metals80% of all elements are metals

NonmetalsNonmetals – Non-lustrous, poor conductors, – Non-lustrous, poor conductors, brittle, some are gasesbrittle, some are gases– HalogensHalogens – Group 7A – Group 7A– Noble GasesNoble Gases – Group 0 – Group 0

Inert – Undergo few chemical reactionsInert – Undergo few chemical reactions– The other nonmetal groups are named for the The other nonmetal groups are named for the

element that they start with. Example: Oxygen element that they start with. Example: Oxygen Family.Family.

MetalloidsMetalloids – Elements that share properties – Elements that share properties with the metals and the nonmetals.with the metals and the nonmetals.– Found on the “stair-step” line.Found on the “stair-step” line.