what is z effective?
Rb+ Al3+ Mg2+ Na+
out of this set which ion is the smallest? which is the largest?
http://en.wikipedia.org/wiki/Effective_nuclear_charge#Calculating_the_effective_nuclear_charge
Z effective, or effective nuclear charge, refers to the net positive charge experienced by an electron in an atom. It is the result of the attraction between the positively charged protons in the nucleus and the negatively charged electrons. Z effective determines the size of an atom or ion.
To determine the trend of Z effective in the given set of ions (Rb+, Al3+, Mg2+, Na+), we need to understand the concept of ionization and the arrangement of electrons in each ion.
First, let's determine the electronic configurations of each ion:
Rb+: [Kr] 5s1
Al3+: [Ne] 3s2 3p1
Mg2+: [Ne] 3s2
Na+: [Ne] 3s1
To analyze the size trend, we should consider the number of electrons and their arrangement. The more electrons a ion has, the larger it tends to be because of increased electron-electron repulsion.
Comparing the given ions, we can see that Rb+ has the most electrons (37 electrons) and Al3+ has the fewest electrons (13 electrons). Therefore, Al3+ is the smallest ion in this set, and Rb+ is the largest ion.
In summary:
- Al3+ is the smallest ion.
- Rb+ is the largest ion.
Remember, this analysis is based on the number of electrons and their arrangement, which determines the effective nuclear charge (Z effective) experienced by each ion.