Internal Examination of a Newly Hatched Alligator. A professional can determine the gender of a very small baby alligator, 6 to 10 inches long. One method is to place the creature on its back and hold open his vent with round-tipped tweezers or forceps, with a helper's assistance.
Technetium is the only element below uranium that does not exist on Earth. It is a synthetic (man-made) element produced in a particle accelerator. For many years, chemists knew that an element with atomic number 43 must exist, based on an empty spot in the periodic table.
Applications. The most useful isotope of technetium is technetium-99m: it has a short half-life and it binds chemically to many biologically active molecules, these properties make it suitable for many medical radioactive isotope tests. Like rhenium and palladium, technetium can serve as a catalyst. For certain reactions, for example the dehydrogenation of isopropyl alcohol, it is a far more effective catalyst than either rhenium or palladium. Of course, its radioactivity is a major problem in finding safe applications.