The median Social Security benefit was $16,295 for men and $11,999 for women in 2012, AARP found. Retirement savings. Just under a third (30 percent) of retirees receive income from either a traditional pension or take withdrawals from a retirement savings account such as a 401(k) or individual retirement account.
The Sodium atom. 1  The Na atom has an equal number of electrons and protons (11 e-and 11 p+). 2  This atom too is unstable because the outer valance shell of electrons has only one electron in it. 3  To be stable the outer shell of electrons should have eight electrons.
The nucleus is the densest part of an atom. Both neutrons and protons have significant mass, while electrons are virtually massless. This model was discovered as a result of the gold foil experiment in 1911 by Ernest Rutherford. Neutrons have no charge, while a proton has a charge of +1. Similarly, electrons have a charge of -1.