Periodic trends
Atomic size
• Atomic radius decrease across a period and increase as it goes down a
period(the trick to this one is that the most electronegative atoms have the
smallest radii because they pull more electrons to themselves with much
force,so the largest atoms are those with the lowest electronegativity)
•
• Like the size of an atom, the size of an ion depends on its nuclear charge, the
number of electrons it possesses, and the orbitals in which the valence
electrons reside
Cation are slightly smaller than their parent atom because they lose an elctron(s)
while ions are slightly bigger because they gain an electron(s)eg. chlorine ion is
bigger than a neutral ion
Isolectronic series- a group of ions containing the number of electrons eg.O2-, F-,
Na+, Mg2+, Al3+ has 10 electrons
Ionization energy- the minimum energy required to remove an electron from a gaseous
atom or ion
• The second ionisation energy, I2, is the energy needed to remove the second
electron, an so forth, for successive removals of additional electrons
Atomic size
• Atomic radius decrease across a period and increase as it goes down a
period(the trick to this one is that the most electronegative atoms have the
smallest radii because they pull more electrons to themselves with much
force,so the largest atoms are those with the lowest electronegativity)
•
• Like the size of an atom, the size of an ion depends on its nuclear charge, the
number of electrons it possesses, and the orbitals in which the valence
electrons reside
Cation are slightly smaller than their parent atom because they lose an elctron(s)
while ions are slightly bigger because they gain an electron(s)eg. chlorine ion is
bigger than a neutral ion
Isolectronic series- a group of ions containing the number of electrons eg.O2-, F-,
Na+, Mg2+, Al3+ has 10 electrons
Ionization energy- the minimum energy required to remove an electron from a gaseous
atom or ion
• The second ionisation energy, I2, is the energy needed to remove the second
electron, an so forth, for successive removals of additional electrons
