2. Periodic Trends Definitions & Trends

3. ELECTRONEGTIVITY Electronegativity is the power of an atom, when in a molecule, to attract electrons to itself.

5. Electronegtivity Increase across ---> Decrease down

7. ATOMIC RADII 1/2 the distance between the nuclei two like atoms

8. Different Atomic Radii

12. Atomic Radii decrease across ------> increase down

13. IONIC RADII The radius of an atom after it has gained or lost an electron and becomes an ion

16. Ionic Radii Increase Across ----> Increase Down

17. IONIZATION ENERGY energy necessary to remove an electron from the neutral atom.

19. Ionization Energy Increase Across ----> Decrease down

20. ELECTRON AFFINITY is a measure of the energy change when an electron is added to a neutral atom to form a negative ion.

22. Electron Affinity Increase Across ----> Decrease Down

24. Electron Shielding The effects of the inner electron shell on the outer most electrons Increase Down Generally decreases across

25. Atomic Number & Mass Atomic Number is the number of protons in an element Atomic mass is the relative average mass of an element

26. Atomic number & mass Increases across ---> Increases down

27. Melting and Boiling Point Generally increase across the chart until d orbitals become half filled then Mp and Bp decrease