periodic trends in the properties of the elements
DESCRIPTION
Reactivity Metals: as you move down a family, reactivity goes up. As you move across a period, reactivity goes down. Brainiac’s Video Nonmetals: as you move down a family, reactivity goes down. As you move across a period, reactivity goes up. Except for the Noble Gases!!!!TRANSCRIPT
Periodic Trends in the Properties of the Elements Reactivity
Metals: as you move down a family, reactivity goes up. As you move
across a period, reactivity goes down. Brainiacs Video Nonmetals:
as you move down a family, reactivity goes down. As you move across
a period, reactivity goes up. Except for the Noble Gases!!!! Atomic
Size Either volume or radius.
Treat atom as a hard marble. As you move down a column on the
periodic table, the size of the atom increases. Valence shell
farther from nucleus. As you move left to right across a period,
the size of the atom decreases. Adding electrons to same valence
shell. Valence shell held closer. Trends in Atomic Size, Continued
Be (4p+ and 4e-) Mg (12p+ and 12e-) Ca (20p+ and 20e-) Group IIA
2e- Li (3p+ and 3e-) Be (4p+ and 4e-) B (5p+ and 5e-) C (6p+ and
6e-)
Period 2 2e- 1e- 3 p+ 2e- 4 p+ 2e- 3e- 5 p+ Li(3p+ and 3e-) Be(4p+
and 4e-) B(5p+ and 5e-) 6 p+ 2e- 4e- 8 p+ 2e- 6e- 10 p+ 2e- 8e-
C(6p+ and 6e-) O(8p+ and 8e-) Ne (10p+ and 10e-) Choose the Larger
Atom in Each Pair
C or O Li or K C or Al Se or I? PracticeChoose the Larger Atom in
Each Pair.
1.N or F 2.C or Ge 3.N or Al 4.Al or Ge PracticeChoose the Larger
Atom in Each Pair, Continued.
N or F, N is further left N or F C or Ge N or Al, Al is further
down & left N or F C or Ge, Ge is further down N or F C or Ge N
or Al Al or Ge?opposing trends Ionization Energy Minimum energy
needed to remove an electron from an atom. Valence electron easiest
to remove. M(g) + 1st IE M1+(g) + 1 e- M+1(g) + 2nd IE M2+(g) + 1
e- First ionization energy = energy to remove electron from neutral
atom; 2nd IE = energy to remove from +1 ion; etc. Trends in
Ionization Energy
As you move down a family, the IE gets smaller. Valence electron
farther from nucleus. As you move left to right across a period,
the IE gets larger. Trends in Ionization Energy, Continued
ExampleChoose the Atom in Each Pair with the Higher First
Ionization Energy
Al or S, Al is further left 1.Al or S 2.As or Sb 3.N or Si 4.O or
Cl,opposing trends Al or S As or Sb N or Si, Si is further down and
left Al or S As or Sb, Sb is further down PracticeChoose the Atom
with the Highest Ionization Energy in Each Pair
1.Mg or P 2.Cl or Br 3.Se or Sb 4.P or Se PracticeChoose the Atom
with the Highest Ionization Energy in Each Pair, Continued
1.Mg or P 2.Cl or Br 3.Se or Sb 4.P or Se ? Metallic Character How
well an elements properties match the general properties of a
metal. In general, metals are found on the left of the periodic
table and nonmetals on the right. As you go left to right across
the period, the elements become less metallic. As you go down a
column, the elements become more metallic Trends in Metallic
Character ExampleChoose the More Metallic Element in Each
Pair
Sn or Te, Sn is further left Sn or Te P or Sb Ge or In S or
Br?opposing trends Sn or Te P or Sb Ge or In, In is further down
& left Sn or Te P or Sb, Sb is further down PracticeChoose the
More Metallic Element in Each Pair
Sn or Te Si or Sn Br or Te Se or I PracticeChoose the More Metallic
Element in Each Pair, Continued
Sn or Te Si or Sn Br or Te Se or I ? Electronegativity Measure of
the pull an atom has on bonding electrons. Increases across the
period (left to right). Decreases down the group (top to bottom).
The larger the difference in electronegativity, the more polar the
bond. Negative end toward more electronegative atom. d+H Fd-
Electronegativity, Continued
2.1 1.0 0.9 0.8 0.7 1.5 1.2 1.3 1.1 1.4 1.6 1.8 1.7 1.9 2.2 2.4 2.0
2.5 3.0 3.5 4.0 2.8 Electronegativity, Continued Melting/Boiling
Point
High melting/boiling point indicates strong bonding Middle of
Periodic Table Low melting/boiling point indicates weak bonding
Lowest MP/BP across period indicates completely filled orbital
Edges of Periodic Table Noble gases have no bonding forces MP/BP
unusually low Melting/Boiling Point