- Substance (chemistry) - Wikipedia
Chemical substances can exist in several different physical states or phases (e g solids, liquids, gases, or plasma) without changing their chemical composition Substances transition between these phases of matter in response to changes in temperature or pressure
- PubChem
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
- Chemistry | Definition, Topics, Types, History, Facts | Britannica
Chemistry is the study of substances—that is, elements and compounds —while biology is the study of living things However, these two branches of science meet in the discipline of biochemistry, which studies the substances in living things and how they change within an organism
- Chemicals, Pesticides and Toxics Topics | US EPA
Learn how to safely handle chemicals, the effects of certain toxins, which substances are controlled or managed, and safer alternatives
- What is a Chemical ? | Nuclear Regulatory Commission - NRC
Chemical changes are different from physical changes, which don't result in a change in substances One example of a physical change is when water freezes into ice While ice may have different physical properties, it is still just water Another example is when you dissolve salt into a cup of water
- What Is a Chemical? Definition and Examples
For example, pesticides in water or artificial colorings in food are “chemicals ” But, chemistry sees chemicals somewhat differently A chemical is a substance with a specific composition It is an element, an alloy, or a compound made up of two or more elements combined in a fixed ratio
- 12 Types of Chemicals Explained | Uses, Examples Safety Tips
Learn about 12 types of chemicals with examples, uses, and safety tips Explore acids, bases, polymers, pharmaceuticals, and more in everyday life
- What Is and Is Not a Chemical? - ThoughtCo
A chemical is any substance that is made of matter, like solids, liquids, or gases Light, heat, and sound are not chemicals since they are not made of matter Chemicals can be both natural, like oxygen, or artificial, like stainless steel
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