3.1 test Flashcards
Deduce which of the following ions has the smallest ionic radius: Mg2+, F-, Na+, O2- (and why)
Mg2+
Why: all have the same electron configuration, so we must look at atomic number. Magnesium has the highest atomic number (12) so the valence electrons are mostly strongly attracted to the nucleus (so smallest radius)
define atomic radius
total distance from the nucleus of an atom to the outermost orbital of its electrons
define ionic radius
the distance between the nucleus of an ion and its outermost shell.
atomic radius trend
increases down a group, decrease left to right across a period (highest in bottom left corner)
define ionisation energy
amount of energy required to remove an electron from an atom/molecule
ionization energy trend
decreases down a group, increases left to right across a period (highest in top right corner)
electron affinity trend
decreases down a group, increases left to right across a period, highest in top right corner (same as ionization energy)
define electron affinity
energy change that results when an electron is ADDED to a gaseous atom (opposite of ionisation energy)
define metallic character
tendency of an element to lose electrons and form cations
metallic character trend
increases down a group, decreases left to right across a period (highest in bottom left corner)
define non-metallic character
the tendency of an element to accept electrons and form negative ions or anions
non-metallic character trend
decreases down a group, increases from left to right across a period (highest in upper right corner, opposite of metallic character)
electronegativity definition
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons
electronegativity trend
decreases down a group, increases from left to right across a period (highest in top right corner)
