1. Periodic table trends Answers

2. Ionization energy vs. atomic number

3. Trends in Ionization Energy
Noble gases exhibit the highest ionization energy
Alkali metals exhibit the lowest ionization energy

4. Atomic radius vs. atomic number

5. Trends in Atomic Radius
Alkali metals have the largest atomic radii
Noble gases have the smallest atomic radius
Atomic radius is inversely related to ionization energy.
As atomic radius increases, ionization energy decreases.

6. Atomic Radius
One half the distance between nuclei of identical atoms that are bonded together (the radius of an atom)
Decreases across a period
increasing positive nuclear charge
more protons but same number of electron shells
Increase down a group
increasing number of electron shells
outer electrons are farther from the nucleus

7. Ionization Energy
The energy required to remove an electron from a neutral atom
IE increases across a period
Atoms are getting smaller, electrons are closer to the nucleus, stronger attractive force
IE decreases down a group
Atoms are getting larger, electrons are farther from the nucleus
Outer electrons becomes increasingly more shielded from the nucleus by inner electrons
Metals have characteristically low IE
Nonmentals have high IE
Noble gases have a very high IE
Stable octet, full valence shell

9. Ionic Radius
Radius of an ion (an atom that has gained or lost electrons)
Cations have a smaller ionic radius than corresponding atom
Protons outnumber electrons
Less shielding of electrons
Therefore, stronger attractive forces
Anions have a larger ionic radius than corresponding atom
Electrons outnumber protons
Greater electron-electron repulsion
Therefore, weaker attractive forces

11. Electron Affinity An atom’s ability to attract an electron
Increases across a period
Atomic radius decreases, stronger attractive forces
Decreases down a group
Atomic radius and shielding by inner electrons increases, weaker attractive force

12. Electronegativity An atom’s ability to attract electrons when bonded
We will explore this more later

13. Electronegativity
Electronegativity