Periodic Trends in Ionic Size

Key Questions

• How does ionic size change?

  An ion's size, compared to its parent atom, depends on whether it gains or loses electrons.

  Gaining electrons increases the apparent diameter, while losing electrons makes the ion smaller than the neutral atom.

  For example if Na loses one electron to form #Na^+#, the latter is smaller than the Na atom.

  When O gains two electrons to form #O^(2-)# the resulting ion is larger.

  Dr_P · · Apr 13 2014

• What happens to ionic size down a group?
• What happens to ionic size across a period?
• How does ionic size change?
• How does ion size affect conductivity?
• Can I determine the ion size by charge?
• Question #78b52
• The primary reason sodium ions are smaller than sodium atoms is that the ion has only two shells of electrons (the atom has three). Some resources suggest the ion gets smaller since there are less electrons being pulled by the nucleus. Comments?
• Which arrangement is in the correct order of radius size? a) Mn > Mn2+ > Cs b) Li+ > Li > Ra c) P < P3– < As3– d) Cr < Cr3+ < Ca e) Al3+ > Al > Si
• Why is the polarizability of an anion directly proportional to its size?
• How would you rank the atomic radius of the following elements from largest to smallest: #Na^(+)# , #F^(-)# , #O^(2-)#, #Al^(3+)#, #Mg^(2+)#, #N^(3-)#?
• Question #a198a
• What would be larger, #K# (parent atom) or #K^+#?
• As a neutral sulfur atom gains two electrons, what happens to the radius of the atom?
• What is atomic radii and how is this impacted in ions?
• How does ionic radius differ from atomic radius?
• How do you find the ionic radius of an element?
• What is the difference between the ionic radius and the atomic radius of an element?
• How would you arrange the ions #N^-3#, #O^-2#, Mg2+, Na+, and F- in order of increasing ionic radius?
• How would you rank these ions according to atomic radius: #K^+#, #Ca^+2#, #P^-3#, #S^-2#, #Cl^-# (from smallest to largest)? Please explain why you chose this order.
• In increasing order, how would you rank these ions according to ionic radius? #Sr^+2#, #Br^-#, #Rb^+#, #As^-3#, #Se^-2#
• How does the ionic radius of a nonmetal compare with its atomic radius? Explain why the change in radius occur?
• Why is the ionic radius of sodium far smaller than its atomic radius?
• Why do the cations of Group 1 increase in radius with increasing proton number?
• Question #65200
• Question #242d1
• What is ionic size?
• How do you determine ionic size?
• How do you arrange elements' ionic size?
• What is ionic size used for?
• What is ionic size in chemistry?
• How do you determine increasing ionic size?
• What happens to ionic size across a period?
• Why does ionic size increase down a group?
• Question #27e4d
• How would you explain ionic radii?
• How does ionic radius increase?
• How do you compare ionic radii?
• How can you determine ionic radii?
• How do you measure ionic radii?
• What does ionic radii mean?
• What is the ionic radii trend?
• Why do ionic radius increase?
• Why is there an ionic radius trend?
• Why is ionic radius smaller?
• How do the ionic radii vary within?
• How does ionic radius change across a period?
• How does ionic radius change across each period?
• How does ionic radius change across the periodic table?
• How does ionic radius change down a group in the periodic table?
• How does ionic radius change if an atom gains electrons?
• How does ionic radius change on the periodic table?
• How does ionic radius change within a group of metals?
• How does ionic radius differ from atomic radius?
• How does the ionic radius of a nonmetal compare with its atomic radius?
• How does the ionic radius of a typical anion compare?
• How do you determine if an ion is larger?
• How does the ionic radius of a typical metal compare with its atomic radius?
• How should particle radius change upon reduction of the particle?
• What is the trend of polarizability as a consequence of changing atomic radius from atom to atom?
• How do the ionic radii of #Fe^(2+)# and #Fe^(3+)# compare?
• Question #f776a
• Question #3ca57