A substance composed of atoms of only one kind, i.e., of identical atomic (proton) number, which therefore cannot be decomposed into two or more elements, and which can lose its chemical properties only by union with some other element or by a nuclear reaction changing the proton number.
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The two major components of the nucleus are protons and neutrons. The number of protons in the atoms of a particular element is always the same, and therefore the physical and chemical properties of the element are always the same.
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Examples of chemical symbols are N (for the element nitrogen), He (for the element helium) and Pb (for the element lead). For more about symbols of the chemical elements see pages listing these: in order of their atomic number, or.
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3) A substance that cannot be decomposed; each chemical element is characterized by the number of protons in the nucleus. See the periodic table and the introduction for elements.
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Other elements exist in the form of molecules. For example many common gases exist as diatomic molecules e.g. oxygen (O2), hydrogen (H2), and nitrogen (N2). Note: This is one of a series of simple pages introducing key concepts in introductory chemistry.
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1 Elements can exist either as atoms (e.g. argon) or as molecules (e.g., nitrogen) 2  Elements cannot be broken down into a simpler type of matter by either physical or chemical techniques - though some larger elements break-down spontaneously due to being radioactive.  Elements are listed in the periodic table.
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Definition of Element. An element is a substance consisting of atoms which all have the same number of protons - i.e. the same atomic number. Elements are chemically the simplest substances and hence cannot be broken down using chemical methods. Elements can only be changed into other elements using nuclear methods. Although an element's atoms must all have the same number of protons, they can have different numbers of neutrons and hence different masses. When atoms of the same element have different numbers of neutrons, they are called isotopes.
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An element is a chemical substance that cannot be broken-down into any simpler substances by chemical reactions. It consists of only one type of atom, though the atoms of an element may, or may not, join together to form molecules (that depends on the particular element and so the structure of its atoms).
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1 Elements can exist either as atoms (e.g. argon) or as molecules (e.g., nitrogen)  Elements cannot be broken down into a simpler type of matter by either physical or chemical techniques - though some larger elements break-down spontaneously due to being radioactive.
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Definition of Element. 1) A substance that cannot be decomposed into simpler substances by chemical means. 2) One of the 116 presently known substances that cannot be decomposed by chemical reaction into a simpler substance. Elements comprise all matter at and above the atomic level.
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element definition chemistry
In chemistry, element is defined as a chemical substance that cannot be broken-down into any simpler substances by chemical reactions. An element is a chemical substance that cannot be broken-down into any simpler substances by chemical reactions.