Plutonium is a radioactive chemical element with symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous....

The MP-443 Grach (Russian: MP-443 Грач, lit. 'rook') or "PYa", for "Pistolet Yarygina" ("Yarygin Pistol"), following traditional Russian naming procedure (Russian: Пистолет Ярыгина), is the Russian standard military-issue side arm. The development was headed by the designer Vladimir Alexandrovich Yarygin. It was developed under designation "Grach" in response to Russian military trials, which began in 1993. In 2003, it was adopted as a standard sidearm for all branches of Russian military and law enforcement, alongside the Makarov PM, GSh-18, and SPS. == Design details == The PYa is a hi...