Chemistry Chapter 5 Section 3
Atomic Radius Definition: ½ distance between center of adjacent nuclei of bonded atoms Trends: p141 Within group, radius increases as go from top to bottom of table Within period, atomic radius decreases as go from left to right in s and p block Transition elements slightly varied due to half and full d and f orbital
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Defined: Amount of energy required to remove one electron from an atom Atom becomes an ion Cation Trends: p 143 Within group: generally ionization energy decreases as go from top to bottom of table Within period: ionization energy increases as go from metal to nonmetal
P 146
Definition: Energy change that occurs when an atom gains an electron Ion formed: anion If electron affinity is positive, energy must be added, and atom is unstable Trends: p 147 Group trends not constant, but more positive number as go from top to bottom of group Across period, largest negative value in group 17 (halogen)
Definition: Electrons available for bonding (usually outer electrons unless transition element) Usually s and p orbital electrons (unless transition) Trends: Within group, valence electrons constant Across period, valence electrons increase from left to right
Cation: Formed by losing electron(s) Smaller than atom due to loss of electron and increased pull by nucleus Anion: Formed by gaining electron(s) Larger than atom because electrons not as strongly held Trends: p 149 Within group, size of ion increases as go from top to bottom Within period, cations formed on left, anions on right
Defined: Measure of ability of atom to attract electrons of another atom Most electronegative element assigned number 4.0 and other calculated wrt this Trends: p 151 Group: electronegativity generally decreases as go from top to bottom of table Period: generally increase from left to right across period
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