Using the Periodic Table

1
Using the Periodic Table

• Trends of alkaline metals and halogens

2
Spotting Trends in the Periodic Table

• Organisation of the periodic table makes it easy
  to spot trends
• Alkali metals are group 1 elements
• Halogens are group 7 elements

3
Atomic Radii

• Atomic radii increases down a group
• Distance to energy level of outer electron
  increases
• Potassium has 1.5 times the atomic radius of
  Lithium
• Iodine has 2 times the atomic radius of Fluorine

4
Ionic Radii

• Ionic radii increases down a group for both
  alkali metals and halogens
• Identical reason behind trend of atomic radius
• Increased ionic radius as outer energy level
  becomes further away from nucleus

5
First Ionisation Energies

• Number of filled orbitals increase down a group
• Outermost electrons orbit further away from
  nucleus
• Less attractive force thus less energy is
  required to remove electron
• Decrease in ionisation energies down a group

6
Electronegativity

• Electronegativity is the ability of an atom to
  attract a bonding pair of electrons to itself
• Electronegativity is relative
• Distance to nucleus determines electronegativity
• Smaller atoms (i.e. smaller atomic radius)
  attracts electrons stronger
• Larger atoms will have less electronegativity
• Electronegativity decreases down a group

7
Bibliography

• Neuss, G (2007). IB Diploma Programme Chemistry
  Course Companion. Oxford Oxford University Press.