Chapter 13- The Periodic Table (1) PDF

THE PERIODIC TABLE Ru V Dmitri Mendeleev and Lothar Meyer  - arranged the known elements in order of their atomic masses in horizontal rows.  - vertical column those elements with similar properties Henry Moseley (England) - determined the atomic numbers of the elements...

THE PERIODIC TABLE Ru V Dmitri Mendeleev and Lothar Meyer  - arranged the known elements in order of their atomic masses in horizontal rows.  - vertical column those elements with similar properties Henry Moseley (England) - determined the atomic numbers of the elements and rearranged the elements bases on their atomic number METALS- composed of more than two-thirds of the elements in the periodic table Typical properties that characterize metals are: Luster Conductivity Malleability Ductility  Electronegativity it is the measure of an atom’s ability to attract a pair of electrons when bonded to another atom  Electronegativity Example: B, C, N, O, F Fluorine (F) - the highest electronegativity  Electron affinity it is the measure of the energy change that occurs when an atom gains a single electron and forms a negative ion  Electron affinity Chlorine (Cl)– has the greatest tendency to gain an electron  Ionization energy it is the energy needed to remove an atom’s most loosely held electron  IONIZATION ENERGY Sodium (Na) - has the least tendency to lose an electron  As you go from left to the right of periodic table, the elements’ ionization energy, electron affinity and electronegativity _______________. INCREASES As you go from top to the bottom of periodic table, the elements’ ionization energy, electron affinity and electronegativity _______________. DECREASES PERIODS AND GROUPS Period Horizontal row There are 7 periods Elements in the same period have the same principal energy Groups Columns of elements IUPAC notation and US notation ways for numbering groups  BLOCKS in the Periodic Table Group A (1A) 2 (IIA): s-block Group 13(IIIA) and 18 (VIIIA): p-block Group 3-12 ( the B groups): d block and f block  BLOCKS in the Periodic Table S and P blocks : are called the representative elemets D-blocks: transition elements F-block: lanthanoids and actinoids or actinides