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CHAPTER 10 PERIODIC PROPERTIES
10-1, 10-2, 10-3, 10-4, 10-5, 10-6
An element's position on the periodic table and its properties are related to its atomic number and its configuration.
Atomic radius increases down a group
In general atomic radius decreases from left to right across a period
the chlorine atom is smaller than the sodium atom
because properties of elements are based on electron configurations, many of these properties are predictable and repeat in periodic patterns. BACK TO THE TOP
the sodium ion is smaller than the sodium atom
the configuration of Na+ is similar to neon
the configuration of Cl- is similar to argon
The chlorine ion is larger than the chlorine atom
ions that are free to move can conduct an electric current
metallic atoms form smaller ions because they tend to lose electrons when forming compounds
nonmetallic atoms form larger ions because they tend to gain electrons when forming compounds
density is another property of elements that varies periodically/ density increase and then decrease as we move left to right across a period of elements
when atoms forms ions they take on noble gas configurations BACK TO THE TOP
10-3 Predicting oxidation numbers
oxidation numbers can be predicted from electron configurations
compounds that contain the H- ion are called hydrides
col 1=+1; col 2=+2; col3=+3; col 4=+2 or +4; col 5=-3; col 6=-2 col 7=-1 col 8=0
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ionization energy is determined by bombardment of the element in the vapor phase by electrons
ionization energy is also measured in eV / 1eV=96.5kJ/mol(one in book)
first ionization energy is the energy needed to remove the most loosely held electron in a atom
ionization energies increase across rows or periods
ionization energies decrease down columns or groups
metals have low ionization energies/nonmetals have high
theories came from experimental evidence on this
the decrease in the force of attraction between outer electrons and the nucleus is due to the presence of other electrons between them and is called the shielding effect
the ease with which an electron can be removed from an atom is related to the type of bond the atom is likely to form with another atom(easy= ionic hard=covalent)
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10-5 Multiple ionization energies
ionization energy increases with the removal of each additional electron/this shows shells in the atom BACK TO THE TOP
electron affinity is the attraction of an atom for an additional electron
metals have low electron affinity/non metals have high
atoms with filled or 1/2filled sublevels tend to have lower electron affinities than neighboring atoms in a period. BACK TO THE TOP
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