1. Chapter 8: Periodic Relationships Among the Elements
Chemistry 1411 Joanna Sabey

2. Periodic Table

3. Periodic Table

4. Periodic Table
An atom of a certain element has 15 electrons. Without consulting a periodic table, answer the following questions: 1) What is the ground-state electron configuration of the element? 2) Is the element diamagnetic or paramagnetic?
1) Write the configuration until the electrons add to 15:
1s2 2s2 2p6 3s2 3p3
2) The last set tells us if they are unpaired:
The element is paramagnetic

5. Isoelectric
Isoelectric: having the same number of electrons, the same electron configuration, as another element.
Label the element the following ions are isolecetric to:
Na+ Ne
Ca2+ Ar F-
O2-
N3-
Fe3+ V
Mn2+

6. Effective Nuclear Charge
Effective nuclear charge (Zeff): the nuclear charge felt by an electron when both the actual nuclear charge (Z) and the repulsive effects of the other electrons are taken into account.

7. Atomic Radius
Atomic radius: one-half the distance between the two nuclei in two adjacent metal atoms or in a diatomic molecule

8. Atomic Radius
Arrange the following elements in order of increasing radius: P, Si, N, O
The trend of the radius is increases down the periodic table and to the left.
O < N< P< Si

9. Ionic Radius
Ionic Radius: the radius of a cation or an ion, usually measured by X-ray diffraction. Cation is always smaller than atom from which it is formed. Anion is always larger than atom from which it is formed.

10. Ionic Radius
For each of the following pairs, indicate which one of the two species is larger:
N3− or F-
N3-
Mg2+ or Ca2+
Ca2+
Fe2+ or Fe3+
Fe2+

11. Ionization Energy
Ionization Energy: the minimum energy required to remove an electron from a gaseous atom in its ground state.
I1 + X (g) X+(g) + e-
I2 + X+(g) X2+(g) + e-
I3 + X2+(g) X3+(g) + e-

12. Ionization Energy Increasing First Ionization Energy

13. Ionization Energy
Which atom should have a smaller first ionization energy: oxygen or sulfur?
Sulfur would have a smaller first ionization energy
Which atom should have a higher first ionization energy: lithium or beryllium?
Beryllium has the higher second ionization energy

14. Electron Affinity
Electron Affinity: the negative of the energy change that occurs when an electron is accepted by an atom in the gaseous state to form and anion.
F (g) + e- F-(g) DH = -328 kJ/mol EA = +328 kJ/mol
O (g) + e- O-(g) DH = -141 kJ/mol EA = +141 kJ/mol

15. Chemical Properties
Diagonal relationships: similarities between pairs of elements in different groups and periods of the periodic table.

16. Group 1A elements React the same way with water and Oxygen gas.
2M(s) + 2H2O(l) 2MOH(aq) + H2(g)
4M(s) + O2(g) 2M2O(s)

17. Group 2A Elements
Calcium, strontium, and barium can react with cold water and acid.
M(s) + 2H2O(l) M(OH)2(aq) + H2(g) M = Ca, Sr, or Ba
Be(s) + 2H2O(l) No Reaction
2M(s) + O2(l)  2MO(s)

18. Group 3A
4M(s) + 3O2(g)  2M2O3(s)
2M(s) + 6H+(aq) 2M3+(aq) + 3H2(g)

19. Group 4A Elements For the metals, tin and lead, they react with acids.
Sn(s) + 2H+(aq) Sn2+(aq) + H2 (g)
Pb(s) + 2H+(aq) Pb2+(aq) + H2 (g)

20. Group 5A Elements N2O5(s) + H2O(l) 2HNO3(aq)
P4O10(s) + 6H2O(l)  4H3PO4(aq)

21. Group 6A Elements
All form 2- anions, and the important commercial suluar formation is sulfur trioxide and water mixture.
SO3(g) + H2O(l)  H2SO4(aq)

22. Group 7A Elements
All of the halogens come as diatomic molecules, X2, they react with hydrogen to form hydrogen halides. Reactivity increases as you go up the periodic table.
X2(g) + H2(g)  2HX(g)

23. Group 8A Elements Completely filled ns and np subshells.
Highest ionization energy of all elements.
No tendency to accept extra electrons

24. Oxides Metal oxides are basic and nonmetal oxides are acidic.
Amphoteric: display both acidic and basic properties.
Classify the following oxides as acidic, basic, or amphoteric:
Rb2O
Basic
BeO
Amphoteric
As2O5
Acidic
Na2O
MgO
Al2O3
SiO2
P4O10
SO3
Cl2O7
Ionic
Molecular
Basic
Amphoteric
Acidic