C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).The new isotope is called "radiocarbon" because it is radioactive, though it is not dangerous.It is naturally unstable and so it will spontaneously decay back into N-14 after a period of time.It takes about 5,730 years for half of a sample of radiocarbon to decay back into nitrogen.
The number of protons in the nucleus of an atom is called its atomic number.
On the other end of this spectrum, only 6% of couples date for 8 years or more before getting engaged.
Though by a relatively small margin, couples in the South spend the least time dating prior to engagement.
Some gift stores and websites have created their own lists of suggestions but nothing as widely recognized as the wedding anniversary symbol list first created by Emily Post in 1922.
However if you have a good thing going, it is important to let your partner in the relationship know that you appreciate them.