Wednesday 2 November 2011

Trends On the Periodic Table

Elements close to each other on the periodic table display similar characteristics.
- There are SEVEN important periodic trends:
1) Reactivity
2) Ion Charge
3) Melting point
4) Atomic Radius
5) Ionization Energy
6) Electronegativity
7) Density
We will only be talking about the first 6, today!

REACTIVITY:
  •  metals and non-metals show different trends.
  •  the most reactive metal is Francium; the most reactive non-metal is fluorine.
ION CHARGE:
  • Elements ion charges depend on their group (column).

MELTING POINT:
  • elements in the center of the table of the highest melting point.
  • noble gases have the lowest melting points.
  • starting from the left to right, melting point increases, until the middle
  • carbon is an exception!
ATOMIC RADIUS:
  • radius decreases to the up and the right.
  • helium has the smallest atomic radius.
  • Francium has the largest atomic radius.

IONIZATION ENERGY:
  • ionization energy is the energy needed to completely remove an electron from an atom.
  • it increases going up and to the right.
  • all noble gases have high ionization energy.
  • helium has the highest ionization energy.
  • francium has the lowest ionization energy.
  • opposite trend from atomic radius.

ELECTRONEGATIVITY:
  • refers to how much atoms want to gain elections.
  • same trend as ionization energy.

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