PERIODIC TABLE 10 VIII 8 VIII 9 VIII. 26 Fe iron. 27 Co cobalt. 28 Ni nickel Ru. 45 Rh rhodium. 46 Pd palladium. rhenium 101.

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1 Tom Penick 0//99 Page of PERIODIC TABLE NONMETALS 8 0 METALLOIDS I A II A H hydrogen.008 III A IV A V A VI A VII A He helium.00 Li lithium.9 Be beryllium 9.0 METALS B boron 0.8 C carbon.0 N nitrogen.0 8 O oxygen.00 9 F flourine Ne neon 0.8 Na sodium.99 Mg magnesium. III B IV B V B VI B VII B I B II B Al aluminum.98 Si silicon 8.09 P phosphorous 0.9 S sulfur.0 Cl clorine. 8 Ar argon K potassium Ca calcium 0.08 Sc scandium.9 Ti titanium.88 V vanadium 0.9 Cr chromium.00 Mn manganese.9 Fe iron.8 Co cobalt Ni nickel Cu copper. 0 Zn zinc.9 Ga gallium 9. Ge germanium. As arsenic.9 Se selenium 8.9 Br bromine 9.90 Kr krypton 8.80 Rb rubidium 8. 8 Sr strontium 8. 9 Y yttrium Zr zirconium 9. Nb niobium 9.9 Mo molybdenum 9.9 Tc technetium 9.9 Ru ruthenium 0. Rh rhodium 0.9 Pd palladium 0. Ag silver Cd cadmium. 9 In indium.8 0 Sn tin 8. Sb antimony.8 Te tellurium. I iodine.9 Xe xenon. Cs cesium.9 Ba barium. Lu lutetium.0 Hf hafnium 8. Ta tantalum 80.9 W tungsten 8.9 Re rhenium 8. Os osmium 90. Ir iridium 9. 8 Pt platinum 9. 9 Au gold Hg Mercury Tl thallium 0. 8 Pb lead 0. 8 Bi bismuth Po polonium 09 8 At astatine Rn radon () 8 Fr francium.0 88 Ra radium.0 0 Lr lawrencium. 0 Unq unnilqu adium () 0 Unp unnilpe ntium () 0 Unh unnilhexium () 0 Uns () 08 Uno () 09 Une () Halogens Alkali Metals Alkaline Earth Metals Noble Gases Lanthanide series La lanthanum Ce cerium 0. 9 Pr praseodymium Nd neodymium. Pm promethium.9 Sm samarium 0. Eu europium.0 Gd gadolinium. Tb terbium 8.9 Dy dysprosium. Ho holmium.9 8 Er erbium. 9 Tm thulium Yb ytterbium.0 Actinide series 89 Ac actinium.0 90 Th thorium.0 9 Pa protactinium.0 9 U uranium Np neptunium.0 9 Pu plutonium. 9 Am americium. 9 Cm curium. 9 Bk berkelium. 98 Cf californium. 99 Es einsteinium. 00 Fm fermium. 0 Md mendelevium 8. 0 No nobelium 9.

2 ATOMS AND QUANTUM MECHANICS Atoms contain a nucleus, core electrons, and valence electrons. Electrons have orbital angular momentum and a spin angular momentum. The spin may be up or down. A covalent bond is formed when two atoms (usually nonmetals) share electrons. An ionic bond results from the transfer of electrons. The group number on the periodic table indicates the number of electrons available for covalent bonding. The elements of group IV are elemental semiconductors (carbon, silicon, germanium). Sp means it can have bonds. Semiconductor compounds must be covalently bonded. MgO and NaCl are not semiconductors because they are salts, ionically bonded. Valence electrons are electrons in the outer shell of an atom that are responsible for the chemical properties of the atom. The metalloids are not metals because there is a gap between the bonding states and the non-bonding states. Metalloids have a small energy gap. Nonmetals (Insulators) have a large energy gap. In metals there is overlap between bonding states. Quantum mechanics is a theory of matter that is based on the concept of the possession of wave properties by elementary particles, that affords a mathematical interpretation of the structure and interactions of matter on the basis of these properties, and that incorporates within it quantum theory and the uncertainty principle called also wave mechanics. ARRANGEMENT OF ELECTRONS An orbital is the volume in space where an electron of particular energy is likely to be found. An electron in one orbital will have a different energy than an electron in another orbital. Electron energies are said to be quantized, that is, they have different sets of energies. If an electron loses or gains energy, it will do so only in regular or set quantities. When all of the electrons in an atom are in their lowest possible levels or positions, the atom is said to be in the ground state. When one or more of the electrons are in higher energy levels, the atom is said to be in the excited state. Four quantum numbers [n, l, m, s] define the orbital location of an electron: The first shell, which is indicated by n=, contains one s sublevel. The s sublevel is spherical in shape and is indicated by l=0 (that's an el). l is the orbital angular momentum and may be an integer from 0 to n-. The second shell, which is indicated by n=, contains an s and a p sublevel. There are three orbitals in a p sublevel. They are shaped like. l= indicates a p sublevel and m l = -,0, are the three sublevels. m is the azimuthal orbital angular momentum quantum number and may be an integer from l to l. The third shell, which is indicated by n=, contains an s sublevel, a p sublevel, and a d sublevel. A d sublevel is indicated by and contains orbitals. Don't worry about the shapes of these orbitals. This pattern of shell construction continues with an f sublevel, indicated by, containing orbitals, a g sublevel, indicated by l=, containing 9 orbitals, and an h sublevel, indicated by l=, containing orbitals. An orbital may have zero, one, or two electrons. The QUANTUM NUMBERS n principal quantum number l orbital angular momentum, 0 to n- m l or m is the azimuthal orbital angular momentum quantum number and represents projection onto an axis, -l m l m s or s spin degeneracy, ±½ particular electron is indicated by a spin angular momentum quantum number, m s or just s, which may be equal to -½or +½. By the Aufbau Principle, electrons are put into lowest orbitals first. By Hund's Rule, when electrons are put into orbitals having the same energy (degenerate orbitals), one electron is put into each orbital before putting a second electron into an orbital. For example, a given p sublevel contains degenerate orbitals. One electron will be placed in each of these orbitals before a second electron is placed in any of them. Atoms with unpaired electrons are paramagnetic. Paramagnetic materials are weakly magnetized when brought into proximity to a magnet. Atoms with no unpaired electrons are diamagnetic. An octet has all orbitals in the first two shells filled. By the Pauli Exclusion Principal, no electrons in a given atom can have all quantum numbers alike. Tom Penick tomzap@eden.com 0//99 Page of

3 Orbital Notation example: ORBITAL NOTATION Ti Titanium s d Orbital Diagram example: Ti Titanium s s p s p s d Electron Configuration Notation example; note the order by shell number: Ti Titanium s s p s p d s Abbreviated Orbital Notation example; the symbol for the noble gas preceeding the element is written in brackets (this is called the core), then additional electrons are shown following: Ti Titanium [Ar] s d Abbreviated Electron Configuration Notation example: Ti Titanium [Ar] d s Ionization energies generally decrease to the lower left. This is because those elements tend to have more shells so that the outer electrons are less tightly held. When an atom loses electrons this happens in the reverse order of electron configuration notation. Outermost electrons leave the atom first, even though a lower shell might not be filled. In the case of our Titanium example, electrons would leave the s shell first although the d shell is not filled. Returning electrons fill the previously vacated spots first, then additional filling is according to Hund's Rule. electron affinity: The measure of an atom's tendency to gain an electron. Thermal energy is released from most atoms when they gain an electron. Exothermic. The higher the electron affinity number, the more likely to gain an electron. atomic radii: Main group radii generally increase to the lower left. Two factors influence the size of the radii: ) The attraction of the positively charged nucleus to the negatively charged electrons ) The negatively charged electrons tend to repel each other. Additional shells tend to resist the effect of ) due to electron shielding. The pull of the nucleus on the outer electrons is partially blocked by the inner electrons. Tom Penick tomzap@eden.com 0//99 Page of

4 CONFIGURATION FOR ATOMS IN GROUND STATE n= n= n= n= ATOMIC # ELEMENT NUMBER OF ELECTRONS SHORTHAND NOTATION H hydrogen s He helium s Li lithium s s Be berylium s s B boron s s p C carbon helium core, s s p N nitrogen electrons s s p 8 O oxygen s s p 9 F flourine s s p 0 Ne neon s s p Na sodium [Ne] s Mg magnesium [Ne] s Al aluminum [Ne] s p Si silicon neon core, [Ne] s p P phosphorous 0 electrons [Ne] s p S sulfur [Ne] s p Cl chlorine [Ne] s p 8 Ar argon [Ne] s p 9 K potasium [Ar] s 0 Ca calcium [Ar] s Sc scandium [Ar] d s Ti titanium [Ar] d s V vanadium [Ar] d s Cr chromium [Ar] d s Mn manganese [Ar] d s Fe iron [Ar] d s Co cobalt argon core, [Ar] d s 8 Ni nickel 8 electrons 8 [Ar] d 8 s 9 Cu copper 0 [Ar] d 0 s 0 Zn zinc 0 [Ar] d 0 s Ga galium 0 [Ar] d 0 s p Ge germanium 0 [Ar] d 0 s p As arsenic 0 [Ar] d 0 s p Se selenium 0 [Ar] d 0 s p Br bromine 0 [Ar] d 0 s p Kr krypton 0 [Ar] d 0 s p Tom Penick tomzap@eden.com 0//99 Page of

5 ELECTRON CONFIGURATION WORKSHEET l=0 l= l=0 l= l=0 l= l=0 l= The purpose of this worksheet is to assist in the visualization of electron configuration in the atoms of elements. The presence of electrons can be indicated by filling in the appropriate Os. The first row of each table is suitable for only the elements of hydrogen and helium. The second row is appropriate for the helium core atoms up through neon (atomic numbers -0). The third row is appropriate for neon core atoms up through argon (atomic numbers -8). Tom Penick 0//99 Page of