The number of possible elements is not known. A very early suggestion made by Elliot Adams in 1911, and based on the arrangement of elements in each horizontal periodic table row, was that elements of atomic weight greater than 256Â± (which would equate to between elements 99 and 100 in modern-day terms) did not exist.
IRS debts can only legally be collected for 10 years, but there are many events that may stop that 10 year clock from running. This is known as tolling the statute of limitations. Events that stop or toll the statute of limitations from running include:
The IRS has a 10 year period of time in which to collect back taxes. After that ten year period of time, the back taxes drop off the tax data base and the debt is legally forgiven and can never be collected. The federal tax liens are also released by statute.