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.
Many of technetium's properties were predicted by Dmitri Mendeleev before the element was discovered. Mendeleev noted a gap in his periodic table and gave the undiscovered element the provisional name ekamanganese (Em).t is the element with the lowest atomic number in the periodic table that has no stable isotopes: every form of it is radioactive. Nearly all technetium is produced synthetically, and only minute amounts are found in nature.