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),
If you made nondeductible contributions to a traditional IRA, you need to attach Form 8606 (PDF), Nondeductible IRAs. Use Form 8880 (PDF), Credit for Qualified Retirement Savings Contributions, to determine whether you are also eligible for a tax credit.Enter the amount of the credit on either Form 1040A or Form 1040.opic 451 - Individual Retirement Arrangements (IRAs). An individual retirement arrangement (IRA) is a tax-favored personal savings arrangement, which allows you to set aside money for retirement.