The third-period elements can hold up up to 18 valence shell electrons. Apparently third-period elements can depart from the octet rule by having more than eight electrons in their valence shells. From the choices you have given, P, Cl, Se and Sn are all capable of having more than 4 pairs of valence electrons.his automatically eliminates carbon, oxygen, boron and fluorine. Tin will tend to form either a +2 or +4 ion, so that's eliminated. Chlorine is in the 3rd period, but because of it's high electronegativity, it will never be the central atom in a compound.
Amount of your reduced Roth IRA contribution. If the amount you can contribute must be reduced, figure your reduced contribution limit as follows. 1  Start with your modified AGI. 2  Subtract from the amount in (1): 3  $183,000 if filing a joint return or qualifying widow(er),f the amount you can contribute must be reduced, figure your reduced contribution limit as follows. 1  Start with your modified AGI. 2  Subtract from the amount in (1): 3  $183,000 if filing a joint return or qualifying widow(er),
Roth IRA. The contribution amount limits to a Roth IRA are the same as those to a traditional IRA. However, your eligibility to contribute to a Roth IRA depends on your income. You can make a full contribution to each Roth IRA as long as your working spouse makes less than $173,000 in 2012.At those levels of modified AGI, the contribution amount begins to phase out, and at $183,000 (2012) you are no longer eligible to make contributions. If the contributing spouse also has an IRA, annual compensation/earned income must exceed the combined contributions the IRAs. 2  Age: The non-working spouse must be under 70 1/2 in the year of the contribution for a traditional IRA.