Selenite tuition class cast name

Selenium Questions Selenium (Se) is a chemical element that falls into the oxygen group (Group 16 [VIa] of the periodic table) and has chemical and physical properties that are similar to sulphur and tellurium. Selenium is an uncommon element that makes up about 90 parts per billion of the Earth’s crust. Selenium is found in metal sulphide ores, where it replaces sulphur to some extent. Selenium is produced commercially as a byproduct of the processing of various ores, most commonly during production. Pure selenide or selenate compound minerals are known, however, they are uncommon. Definition: Selenium is a photosensitive element that occurs in both crystalline and amorphous forms and is utilised mostly in glass, semiconductor devices, and alloys. It is derived primarily as a by-product of copper refining. Selenium Chemistry Questions with Solutions Q1: What are the atomic number and atomic mass of selenium? Answer: Atomic Number 34 Atomic Mass 78.91 Q2: What are the chemical properties of selenium? Answer: Group 16 Melting point 494 K Period 4 Boiling point 958 K Block p Density (g cm −3) 4.81 g/cm 3 Atomic number 34 State at 20°C Solid Electron configuration [Ar] 3d 104s 24p 4 Q3: Which of the following elements does not belong to group 16 of the periodic table? a) Oxygen b) Sulphur c) Phosphorus d) Selenium Answer: c Explanation: Oxygen (O), Sulphur (S), Selenium (Se), Tellurium (Te), and Polonium (Po) make up Group 16 of the periodic table. The elements of this group ...