A compound is a substance composed of two or more elements chemically bonded together in a fixed proportion by mass. The elements that form a compound retain their individual identities but combine to create a new substance with unique properties different from the original elements.
The elements that are used to form compounds are those found on the periodic table, which is a comprehensive listing of all known elements organized based on their atomic numbers, electron configurations, and recurring chemical properties.
There are 118 known elements, each with its unique set of properties and characteristics. However, not all elements form compounds. Some elements, like noble gases (Group 18), are highly stable and do not readily react with other elements.
The majority of compounds are formed by the combination of two or more non-metallic elements. These compounds include oxides (compounds containing oxygen), sulfides (compounds containing sulfur), halides (compounds containing halogens like chlorine, fluorine, bromine, and iodine), and many more.
Compounds can also be formed between metals and non-metals. These compounds, known as metallic compounds, include salts (compounds formed by the reaction of a metal with a non-metallic acid), bases (compounds that react with acids to form salts and water), and many other types of compounds.
In summary, compounds are formed by the chemical combination of two or more elements. The elements that form compounds are those found on the periodic table, excluding noble gases. While some elements do not readily form compounds, most elements can combine to create a diverse array of compounds with unique properties and applications.
