Made the FIRST periodic table
1869 Mendeleev organized the periodic table based on the similar properties and relativities of certain elements Later, Henri Moseley organized the elements by increasing atomic number
Periodic Table Elements in the same group have similar chemical properties Groups: the columns in the periodic table 8A He Ne Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Xe Periods: the rows in the periodic table Rn
H Li Be Main Group or Representative Elements B C N O F He Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Transition Metals He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Lanthanide Series He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Actinide Series He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
ALKALI METALS NOBLE GASES ALKALINE EARTH METALS CHALCOGENS HALOGENS
H Alkali Metals He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Alkaline Earth Metals He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Halogens He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
H Noble Gases He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
METALS METALLOIDS B NONMETALS Si Ge As Sb Te Po At
Metals Left side of the periodic table except H Properties: lustrous (shiny) good thermal and electrical conductors malleable solids at RT except Hg = liquid
Non-Metals Right side of table plus H Properties: Dull appearance Brittle when solid Do not conduct heat or electricity well Primarily solids or gases at RT Bromine = liquid
Metalloids Stair step between metals and non-metals Properties in between metals and non-metals Si: brittle but semi-conductor
S P D F
Energy 1. Aufbau Principle - an electron occupies the lowest-energy orbital that can receive it 3p 3d 3s 2p 2s 1s
2. Pauli Exclusion Principle - no two electrons in the same atom can have the same set of four quantum numbers **Opposite spin states!!** 1s
3. Hund s Rule orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state 3p Each electron has its own orbital All are in the same spin state
Shortcut (shortened) Notation: Use closest Noble Gas before the element For bromine: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 Closest Noble Gas before the element: Argon: Shortcut Notation: 1s 2 2s 2 2p 6 3s 2 3p 6 [Ar] 4s 2 3d 10 4p 5
For sodium: [Ne]3s 1 1 valence electron! For potassium: [Ar]4s 1 1 valence electron!
For aluminum: [Ne]3s 2 3p 1 For gallium: 3 valence electrons! [Ar]4s 2 3d 10 4p 1 3 valence electrons!
For chlorine: 1s 2 2s 2 2p 6 3s 2 3p 5 For bromine: 7 valence electrons! 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 7 valence electrons!
A way to represent the number of valence electrons an atom contains
Number of Electrons in the Ending Configuration Lewis Dot Diagram 1 Li 2 Mg 3 Al 4 Si
Number of Electrons in the Ending Configuration Lewis Dot Diagram 5 N 6 O 7 F 8 Ne
A few exceptions: Chromium Would expect: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4 Actually: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 1s 2s 2p 3s 3p 4s 3d
Periodicity We can tell a lot about particular properties of elements simply based upon where they are on the periodic chart. There are five general trends that can be predicted: atomic size, ionization energy, electronegativity, electron affinity, and reactivity.
It all relates to something called effective nuclear charge Z eff. Think of the effective nuclear charge as the pull that the outer electrons feel from the nucleus. Nuclear pull: The pull/attraction between the + protons and the electrons.
Atomic Radius Measures the size of an atom Measured from one nucleus to the next
K has 19 + charges As you go from left to right, the pull on the outer electrons (from the nucleus) is greater. It requires more energy to hold onto those electrons, which causes the atomic size to be smaller. Br has 35 + charges
ATOMIC SIZE DECREASES
Therefore, as you move down the chart the atomic size increases. As you move down the chart, the number of energy levels increases.
http://encarta.msn.co
Ignore noble gases when going left to right. Memorize fluorine as the smallest element on the chart. Memorize francium as the largest element on the chart.
Ionic Radius The size of ions (charged atoms resulting from a change in electrons) 2-1+
+: Cation: lost electron(s) -: Anion: gain electron(s) +2 < +1 < 0 < -1 < -2
The amount of energy required to remove valance electrons. The amount of energy required to create an ion. The greater the effective nuclear charge (Z eff ), the tighter the valance electrons are being held. The tighter the electrons are being held, more energy is required to remove them.
The amount of energy required to remove the outermost electron from an atom http://nanotech.sc.mahidol.ac.th/genchem/bonding1/ie.jpg http://www.physchem.co.za/atomic/periodicity.htm
Z eff increases Ionization Energy increases
Effective nuclear charge decreases (Z eff ). Ionization energy decreases. As the valance electrons get farther away, the force of attraction (Z eff ) between the nucleus and the electrons gets weaker. Thus, less energy is required to remove the electrons. F will have the highest IE and Fr will have the lowest.
Affinity tends to increase across a period Affinity tends to decrease as you go down a group Electrons farther from the nucleus experience less nuclear attraction Some irregularities due to repulsive forces in the relatively small p orbitals
Ze ff increases Electron Affinity increases
Effective nuclear charge decreases (Z eff ). Electron Affinity decreases.
The attraction an atom has for an electron in a bond
Increases with an increased effective nuclear charge. Decreases with a decreased effective nuclear charge.
Defined as how easily an atom can lose or gain electrons in order to complete the octet. Metals will lose electrons until they re left with 8 valance. Nonmetals will gain electrons until they re left with 8 valance. Metalloids can do both.
Reactivity decreases with increased Z eff Reactivity increases with decreased Z eff Since metals lose electrons, reactive metals are those metals that can easily lose their electrons.
Nonmetals gain electrons to complete the octet. Smaller nonmetals can gain electrons easier than larger nonmetals due to an increased effective nuclear charge (Z eff ).
Summation of Periodic Trends Z eff, IE, and EN follow the same trends. Atomic Radius is opposite. Electronegativity