Dobereiner developed concept of Triads (groups of 3 elements with similar chemical properties) Average of 1st and 3rd

Transcription

1 Unit Early 800's Dobereiner developed concept of Triads (groups of elements with similar chemical properties) atomic mass atomic mass Ca 0. S. Sr Average of st and rd Se Ba 7. Te 7. *useful for predicting undiscovered elements (0. + 7) = 88. Actual 87.

2 Newlands Octaves (8) Newlands arranged the elements then known in the following manner.(seven groups of 7) Li Be B C N O F Na Mg Al Si P S Cl K Ca Every 8th element has repeating chemical and physical properties dımıtrı mendeleev was a Russian chemist and inventor. He is credited as being the creator of the first version of the periodic table of elements. Using the table, he predicted the properties of elements yet to be discovered.

3 Henry Moseley-Modern Periodic Table Modern Periodic Law Elements are arranged in order of increasing atomic number and repeating chemical and physical properties.

4 OLD Mendeleev (atomic mass) NEW Moseley (atomic number) Hg (Tells you the valence shell) Period #'s horizontal rows (read left to right) H *A groups tell you the # of valence electrons Metals Non metals Metalloids Groups / Families Read top to bottom

5 Representative elements * Group A elements * Represent a wide range of physical and chemical properties * metals, nonmetals, metalloids Metals * left side of pd table * ductile & malleable * Usually shiny (not shinny!!) * Good Conductors * Mostly solids * LOSE electrons to (not loose!) form bonds (form CATIONS) Nonmetals * right side of pd. table * Brittle * Dull * Poor Conductors * Mostly gases * GAIN electrons to form bonds (form ANIONS) Semi Metals/Metalloids * Share properties of both metal and non metals * Found on the line b/w metal and non metals (except Aluminum, Al!!!)

6 0 H Alkali Metals Alkaline Earth Metals Group/Family Names Transition Metals B C N 0 Chalcogens Halogens Noble Gases Inner Transition Metals (Tells you the valence shell) Periods horizontal rows (read left to right) A groups tell you the # of valence electrons Read top to bottom Groups / Families

7 Write ONE of these group names on the back of a single per. table. card! then COLOR it's column/block shown on the front of the card!!. How do you read a period? Horizontal or vertical? (circle one). What halogen has a valence shell of?. What group of elements lose electrons? What is the charge?. Elements in the same groups have the same number of what?. What Noble Gas is in Period?. The current periodic table is arranged in order of increasing what? 7. What Alkali Metal is in Period? 8. The valence shell is the same as what? 9. Fe is in what group? 0. What element has a valence shell of and valence electrons?. What group of elements LOSE valence electron? What is the charge? 7

8 s s s s s s s from the period number "d" block d d d d d d d 7 d 8 d 9 d 0 d d p p p p p p p p p p "p" block Ne Ar Kr Xe s 7s "s" block d d from the period number p 7p f f f f f f f 7 f 8 f 9 f 0 f f f f f f "p" block Rn 7 s block A s s s s s s 7s d Block ( energy level) f Block p Block A f ( energy levels) f d d d d 8A A A A A He 7A Ne p p p p p Ar Kr Xe Rn 8

9 Noble Gas Notation shortened electron configuration that uses Noble gases as a reference point + Example: + Most of the time, this will save you writing (old way) Sn s s p s p s d 0 s s d 0 p Using NGN: Sn [Kr] s d 0 p ions formed by group in red He Ne Ar Kr Sn Xe Rn 7 He Ne Ar Kr Xe 7 Rn 7 9

10 Atomic Radius the size of an atom or ion. + Cations get smaller when they lose an electron (metals) Anions get bigger when they gain an electron (non metals) (Radius of IONS only whichever has the most electrons is larger) Electronegativity(EN) the tendency for an atom to attract electrons to itself while bonded. Ionization Energy(IE) is the energy needed to remove an electron from an atom while bonded. Electron Affinity (EA) is the energy given off when a neutral atom GAINS an extra electron to form a negatively charged ion. Atomic radius increases Ionization Energy and Electronegativity decrease Atomic radius decreases Ionization Energy and Electronegativity increase Biggest (highest AR) Lowest IE Lowest EN / EA Most reactive metal Periodic Trends Most reactive non metal Smallest (lowest AR) Highest IE Highest EN /EA 0

11