1. UNIT VIII The Periodic Table and Chemical Bonding Lesson#3

2. VIII.2 THE PERIODIC TABLE Organized according to ATOMIC # --- Mendeleev Periodic Law : the properties of the elements recur periodically when the elements are arranged in increasing order by their atomic numbers

3. A. The Modern Periodic Table INCREASING REACTIVITY

4. Trends in the Periodic Table: PERIOD: is the set of all the elements in a given row going ACROSS the table FAMILY (group): is the set of all the elements in a given column going down the table

5. VIII.2 THE PERIODIC TABLE Metals, Nonmetals, and Semiconductors: Metals: malleable (flatten into sheets) ductile opaque conduct electricity * solid at room temp (except.... ) Lustre * Metals conductivity decreases with an increase in temp

6. VIII.2 THE PERIODIC TABLE Metals, Nonmetals, and Semiconductors: Nonmetals At room temperature: solid, liquid or gas poor conductors Semiconductors aka “metalloids” or “semimetals” conductivity increases with an increase in temp

7. VIII.2 THE PERIODIC TABLE

8. TRENDS: 1. Properties of elements change from metallic to nonmetallic going from left to right

9. VIII.2 THE PERIODIC TABLE 2. Elements become more metallic (or better metals) going down a family in the periodic table

10. VIII.2 THE PERIODIC TABLE 3. The size of the elements radius decreases going across a row and increases going down a family

11. Why does the size of the element increase going down? Electron Shells Each period on the periodic table represents a different electron shell The more down you go, the more shells there are. Therefore, the larger the atom’s size will be. As you go down the periodic table, the atoms get BIGGER

12. W HY DOES THE SIZE OF THE ELEMENT DECREASE GOING ACROSS ? F ROM LEFT TO RIGHT ? Atomic radius explained…  Going from left to right on the periodic table, the atomic number increases and the _________ charge on the nucleus increases As you go across the periodic table, the atoms get SMALLER because….?

13. A. The Electronic Nature of Chemical Bonding Electrostatic Force : is a force existing as a result of the attraction or repulsion between 2 charged particles + and – ATTRACT (different charges) + and + REPEL – and – REPEL The closer the charges are, the greater the force The greater the charge, the greater the force

14. E LECTRON SHELLS OPEN SHELL : is a shell containing less than its maximum number of electrons CLOSED SHELL: is a shell containing its maximum number of electrons Ex: noble gases

15. Valence Electrons: Total number of electrons in open shells that can participate in a chemical bond. Use the periodic table to determine the number of valence electrons (for s and p orbitals) Atom Group KIKI Ca 2 Ga 3 Ge 4 As 5 Se 6 Br 7 Kr 8 # of valence e- (e in outter shells)

16. C HLORINE AS AN EXAMPLE Draw the valence electrons for Chlorine.

17. VIII.3 CHEMICAL BONDING Valence: The number of unpaired valence electrons on the atom ( COMBINING CAPACITY ) each ORBITAL holds 2 e- only dealing with s and p orbitals so the maximum number of electrons in a shell is: _______________ only UNPAIRED electrons take part in bonding! ex: BF

18. VIII.3 CHEMICAL BONDING Going across periodic table the valence of an atom: The valence is the combining capacity! Group 1Group 2Group 3Group 4Group 5Group 6Group 7Group 8 12343210

19. A few more things to know… Ionization Energy (IE) The minimum energy required to remove an electron from a an atom or molecule in the gaseous state. Ca + energy → Ca 2+ + 2e -

20. IONIZATION ENERGY Going ACROSS the periodic table the ionization energy (IE) increases Why? Going DOWN the periodic table the IE decreases Why?

21. Ionization Energy He has the GREATEST ionization energy Fr has the LEAST ionization energy

22. H OMEWORK These are fast questions to answer, so solve them all Hebden p. 164 # 35-39 Hebden p. 166 # 42-45 and p. 168 # 47 Hebden p. 168 # 48-51 and p. 170 # 53-56