Bohr Model of the Atom of Helium

**Symbol:** He **Atomic number:** 2 **Relative atomic mass:** 4.003 **Description:** Helium is an inert, colorless, odorless, tasteless and lightweight monoatomic gas. Among all known gases, it has the lowest melting and boiling points.. **Applications:** Helium is commonly used to fill balloons and airships. It is also used (in combination with other inert gases) in lamps and laser tubes. In its liquid state, helium exhibits excellent electrical conductivity (superconductivity) and has an exceptionally low viscosity (superfluidity). **Occurrence:** Helium is a rare element on Earth, classified as a noble gas. However, it is the second most abundant element in the universe, after hydrogen. According to Bohr's atomic model, electrons in an oxygen atom move in fixed, circular orbits with constant energy. A helium atom consists of two positively charged protons, two neutrons, and two negatively charged electrons. The protons and neutrons are located in the nucleus, while the electrons move around the nucleus in defined circular paths.