Pure Hydrogen:
* Liquid hydrogen: Used as a rocket fuel and in some scientific applications.
* Gaseous hydrogen: Used in various industrial processes like fuel cells and ammonia production.
Hydrogen as a Component:
* Water (H₂O): The most common compound containing hydrogen.
* Hydrocarbons: Found in fossil fuels like natural gas, petroleum, and coal.
* Organic Compounds: Nearly all organic molecules contain hydrogen, including carbohydrates, proteins, fats, and DNA.
* Ammonia (NH₃): Used in fertilizers and other industrial applications.
* Methanol (CH₃OH): Used as a fuel and in the production of various chemicals.
* Hydrogen Peroxide (H₂O₂): A common antiseptic and bleaching agent.
Items not made of hydrogen:
* Metals: While some metals might contain trace amounts of hydrogen, they are primarily composed of other elements.
* Ceramics: Composed of non-metallic materials.
* Plastics: While some plastics contain hydrogen as a component, they are primarily composed of carbon and other elements.
Remember that hydrogen is a key component in many essential materials but seldom found in pure form in everyday items.
