Chemical Substances

Chemical substances are forms of matter that have a defined composition and distinct properties. They can be elements, like oxygen or gold, which consist of only one type of atom, or compounds, like water or table salt, made from two or more different elements chemically combined in fixed ratios. Each chemical substance is characterized by its properties, such as melting point, boiling point, and reactivity. Understanding these substances is essential for various fields, including chemistry, biology, and material science, as they are the building blocks of everything around us, from the air we breathe to the products we use daily.