1. Trends of the Elements on the Periodic Table

2. Atoms want to gain stability
ECN trends
Periods
Groups

3. What allows atoms to be able to achieve s2p6
Remember: it takes energy to remove an e- from an atom

4. Atomic radii Size of atoms
Measured as distance between nuclei of 2 of the same atoms sitting next to each other

6. Differs across a Period and down a Group
Follows a trend
Period

7. Radii of Ions Metallic Ions On the left and center of the P.T.
Ions formed by a loss of e-
Ions are smaller than the atoms from which they were formed
Nonmetallic ions
Located on right side of P.T.
Formed by a gain of e-
Ions are larger than the atoms they were formed from

8. Metallic ions have an outer level that resembles Noble Gas at end of preceding period
Nonmetallic ions have an outer level that resembles Noble Gas at end of same period
HW read pgs pg.255 # 1,2 pg. 257 # 3,4

9. Ionization Energy
amount of energy required to remove an e- from an atom
First ionization energy
Energy required to remove the most loosely held e- from an atom
Atoms/ions have multiple ionization energies

11. The first ionization energy tends to increase as atomic number increases in a period
Ionization energy tends to decrease as atomic number increases in a group
Metals are characterized by a low 1st ionization energy
Nonetals are characterized by a high 1st ionization energy

12. Factors affecting Ionization Energy
Nuclear charge
strength of charge relative to an atoms position in a Period
Stronger relative charge, greater ionization energy

13. Shielding effect
Dependent on number of energy levels
More levels, more shielding
Greater the shielding
Lower the ionization energy of the atom

14. Radius
Distance from nucleus to valence electron(s)
Short distance(small atom)
Large distance(large atom)

15. Sublevels
s,p,d,f
Act as shields within energy levels
Full or half-filled sublevels
More stable
Require additional energy to remove e-
Ex. Noble gases, Cu & Zn(d sublevel)

16. Electron Affinity Ability of atom to accept e- Greater nuclear charge
Greater affinity
Small atoms (non-metals): high
Large atoms (metals): low

17. Group 1 Group 2 Alkali metals Largest atoms in group Lowest affinity
Alkaline earth metals
2nd largest group atoms
More affinity than Group 1
Still very low

18. Group 16 Group 17 Very small atoms in Group High affinity Halogens
Smallest atoms of any Group
Greatest affinity

19. Group 18 Noble gases Little or no affinity Already have s2p6 ECN
Are highly stable
Do not need e-

20. Electronegativity
A measure of the attraction for an e- of another atom during the bonding process
The greater the electronegativity of an atom,the greater the attraction for another atoms e-
Atoms with high Ionization energy have high Electronegativity

21. Metals
Large atoms
Low ionization energy and low electronegativity
Let e- go in bonding
Non-metals
Small atoms
High ionization energy and high electronegativity
Hold on to e- and pull hard on other atoms e-
F is the highest, O is second
Noble gases have no electronegativity