Of the first 83 elements in the periodic table, 80 have isotopes considered to be stable. Technetium, promethium (atomic numbers 43 and 61, respectively) and all the elements with an atomic number over 82 only have isotopes that are known to decompose through radioactive decay.nly 13 of the 38 known-but-unstable elements (assuming the total number of elements is 118) have isotopes with a half-life of at least 100 years. Every known isotope of the remaining 25 elements is highly radioactive; these are used in academic research and sometimes in industry and medicine.
Cortisol Saliva Test. This test uses a saliva sample to measure a personâs Cortisol level. Saliva testing can provide just as accurate a measurement of adrenal hormones like Cortisol as a blood test can.
The cortisol level test is done to check if cortisol production levels are either too high or too low. There are certain diseases, such as Addisonâs disease and Cushingâs disease, which affect the amount of cortisol produced by the adrenal gland. The test is used in the diagnosis of these diseases and as a way to assess the functioning of the adrenal and pituitary glands.