Beryllium-9

Beryllium or Be (Be is Beryllium's element symbol) is a metallic atom that was discovered by Fredrich Wohler. Beryllium is used for mainly spacecraft, missiles, and aircraft. Beryllium is classified as an alkaline atom. It is found in the second group of the periodic table along with all of the other atoms alkaline atoms. Beryllium's atomic mass is 5, and it's atomic number is 4. Beryllium also has 4 protons, 4 electrons, and 5 neutrons. Beryllium's density 1.8477 g. Therefor, since water's density is 1 gram and Beryllium's density is more by 0.8477, Beryllium would sink if it was placed in water.