ionization energy

[OnlyDrilling]

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Do alkali (group 1) metals have a low first ionization energy or is it group 2 (alkaline earth metals)?? Im thinking its group 1 but not sure...help someeeone please

 

[krajapak]

-Alkali metals (group 1) have a lower ionization energy than Group 2.
-ionization energy increases from left to right, and bottom to top.

 

[OnlyDrilling]

Thats what i thought, thank you for helping me out

 

[iwannabadentist]

if you dont want to simply memorize this trend (or any other measly fact for that matter) try to understand the concept. all elements want a full octet of electrons (except H, He, Li, Be, and B...who are happy with 2 electrons in the outermost shell...and 6 for B...but it can take more if it is forced to)...which is like to refer to as their "happy state." ionization energy is the amount of energy it takes to rip off an electron from the outermost shell rite. so the alkali metals have only 1 outermost electron....so if u rip that off...they will have the same electron configuration as a noble gas, which is their happy state. so they are really really willing to give that one electron away...so the ionization energy is very low. alkali earth metals...have 2 valence electrons so they have more of a "eh...w/e i'll be happier if i can find a partner that wants to take both my electrons instead of just one" attitude...meaning their first ionization energy will be not as low as alkali. BUT...their (alkali earth) second ionization energy is MUCHH lower than alkali ...because now they only have 1 valence electron and they are much more willing to give it away to get to their happy state...whereas the alkali metals are already in their happy state after losing 1 electron. hope this story helped...lol i dont like to memorize facts straight up...i like to understand things....its a lot easier to remember that way.

 

[Svart Aske]

alkali earth metals...have 2 valence electrons so they have more of a "eh...w/e i'll be happier if i can find a partner that wants to take both my electrons instead of just one" attitude...meaning their first ionization energy will be not as low as alkali. BUT...their (alkali earth) second ionization energy is MUCHH lower than alkali ...because now they only have 1 valence electron and they are much more willing to give it away to get to their happy state...whereas the alkali metals are already in their happy state after losing 1 electron.

Are you sure about this? I was under the impression that the second ionization energy is ALWAYS higher than the first, because now that you have removed an electrons, the positive nucleus holds on to the remaining electrons more tightly.

EDIT: I just realized that the logic I employed above is not clear, since removing an electron makes a cation. Still, I'm pretty sure that the second IE is always greater, because you're further "destabilizing" ion.

 

[gentile1225]

a good way that i analyze ionization energies is to think of them as loose teeth. Group 1 metals have the lowest first ionization energy because they have one loose tooth so it will remove an electron in the outermost shell most readily. Group 2 will have 2 low ionization energies. The third ionization energy of Group 2 metal will be relatively large compared to the first and second and thats how you can tell which group the element is in.

know other definitions such as ionization energy, electron affinity, binding energy, etc.

good luck studying!

 

[klutzy1987]

Are you sure about this? I was under the impression that the second ionization energy is ALWAYS higher than the first, because now that you have removed an electrons, the positive nucleus holds on to the remaining electrons more tightly.

EDIT: I just realized that the logic I employed above is not clear, since removing an electron makes a cation. Still, I'm pretty sure that the second IE is always greater, because you're further "destabilizing" ion.

When you remove the secong electron from a group 2 metal you are actuallt stabilizing the ion because you are giving it a noble gas configuration. Ca2+ is more stable than Ca. The first ionization energy of Ca will be higher than the second. However the third will be exponentially higher than the second.

 

[Svart Aske]

When you remove the secong electron from a group 2 metal you are actuallt stabilizing the ion because you are giving it a noble gas configuration. Ca2+ is more stable than Ca. The first ionization energy of Ca will be higher than the second. However the third will be exponentially higher than the second.

There is at least one source that says the second ionization energy is higher: http://www.chemicool.com/elements/calcium.html

 

[iwannabadentist]

im sorry...i might have been misunderstood. in an ABSOLUTE sense...2nd IE is always higher...because you have to take into account the first IE. meaning the 2nd IE would be the sum of the energy required to remove the first electron PLUS the energy required to remove the second electron...so obviously it will be higher than the first IE alone. What I meant was...the energy required (for alkali earth metals) to go from a 0 state to a +1 state is much higher than the energy required to go from a +1 to a +2 state. hopefully that clears it up...

 

[adizzle87]

On a related note, know that Ionization Energy is related to but not the same as Electron Affinity. Both have the same trend, as you go right they both increase. However know that Noble Gases have NO electron affinity because their full octet can't take any more. Therefore F is the most electronegative but the noble gases always have the highest ionization energy in the same period.