Chemical substance - Wikipedia
WebA chemical substance is a unique form of matter with constant chemical composition and characteristic properties. [1] [2] Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. [3]
Chemistry - Wikipedia
WebChemistry. Part of a series on. Chemistry. Science of matter. Index. Outline. Glossary. History ( timeline) Key components. Branches. Research. Chemistry portal. Category. v. t. e. Chemistry is the scientific study of the properties and behavior of matter. [1] .
What Is a Chemical? Definition and Examples - Science Notes and …
WebOct 15, 2023 · It is an element, an alloy, or a compound made up of two or more elements combined in a fixed ratio. For instance, water (H 2 O) is a chemical because it consists of hydrogen and oxygen combined in a 2:1 ratio. All matter either is a …
Chemical compound | Definition, Examples, & Types | Britannica
WebMar 11, 2024 · chemical compound, any substance composed of identical molecules consisting of atoms of two or more chemical elements. water molecule.
What is a Chemical ? | NRC.gov
WebMar 19, 2020 · A chemical is any substance that has a defined composition. In other words, a chemical is always made up of the same "stuff." Some chemicals occur in nature, such as water. Other chemicals are manufactured, such as chlorine (used for bleaching fabrics or in swimming pools).
PubChem
WebPubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.
What Is and Is Not a Chemical? - ThoughtCo
WebDec 7, 2019 · A chemical is any substance consisting of matter. This includes any liquid, solid, or gas. A chemical is any pure substance (an element) or any mixture (a solution, compound, or gas). They can either occur naturally or …
Molecules, salts, compounds, and chemicals (article) - Khan …
WebLearn how to describe different chemical substances. Chemistry is the study of matter in all its forms. So, it’s no surprise that chemists need different terms to describe the various ways matter can be structured. Let’s take a closer look at …
Chemical Definition - Chemistry Glossary - ThoughtCo
WebMay 8, 2019 · Anything consisting of matter is a chemical. Any liquid, solid, gas. A chemical includes any pure substance; any mixture. Because this definition of a chemical is so broad, most people consider a pure substance (element or compound) to be a chemical, particularly if it is prepared in a laboratory.
Guidance on chemicals and health - World Health Organization …
WebChemical safety. In 2019, a small number of chemicals for which data are available were estimated to cause 2 million deaths from a variety of health outcomes including poisonings, heart diseases, chronic respiratory diseases and cancers. Chemical pollution also negatively impacts a range of facets of the ecosystem, which can harm human health.
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