Is helium gas a pure substance or a mixture

Helium gas, with its characteristic light and buoyant nature, is a fascinating element often associated with balloons, blimps, and scientific experiments.  The question of whether helium gas is a pure substance or a mixture is an important one in chemistry.  To answer this question, we need to understand the fundamental differences between pure substances and mixtures.

      A pure substance is defined as a material that is made up of only one type of particle.  This could be a single element or a compound, but in both cases, the material is composed of identical particles.  On the other hand, a mixture is a combination of two or more substances that are physically mixed together but not chemically combined.  The individual components of a mixture can be separated through physical means.

      When it comes to helium gas, it is a pure substance.  Helium, with the atomic number 2 and the symbol He on the Periodic Table, is an element in its most basic form.  It exists as a single type of particle and is not composed of multiple substances mixed together.  In its gaseous state, helium consists of helium atoms that are not chemically bonded to any other type of particle.

      Moreover, helium gas is relatively inert, meaning it does not easily react with other substances.  This further supports the fact that it is a pure substance since pure substances tend to have consistent and predictable chemical properties.

      In conclusion, helium gas is a pure substance because it consists of only one type of particle - the helium atom.  It is not a mixture because it does not contain multiple substances that are physically mixed together.  Understanding the difference between pure substances and mixtures is crucial in chemistry and helps us appreciate the unique properties and behaviors of various materials.