Likewise, we can calculate the atomic weight of any element considering the isotopes and their abundance. The modern periodic system is formed on the basis of atomic number and electronic configuration of the atom but Mendeleev classification is based on atomic weight or mass. Atomic weight and atomic mass are two important terms that we often use in chemical calculations. Learn a new word every day. 2. Atomic Number of Elements. So, for these elements, the total nucleon count (sum of the number of protons and neutrons in the atomic nucleus) is usually cited in the place of the standard atomic weight. Atomic Number Density. Learn more. For synthetic elements, there is no natural isotope abundance. Under the article Measure, (q.v.) Definition of Atomic Mass Atomic mass is defined as the number of protons and neutrons contained in an individual unit of a substance. The usual abbreviation for atomic weight in texts and references is at wt or at. Atomic Number of Elements. What made you want to look up atomic weight? Information and translations of atomic weight in the most comprehensive dictionary definitions resource on the web. All Free. Usage examples of "atomic weight". Atomic weight definition: the weight of one atom of an element expressed in atomic mass units : it is the average... | Meaning, pronunciation, translations and examples Definition of atomic-weight noun in Oxford Advanced American Dictionary. Atomic weight is the average mass of atoms of an element, calculated using the relative abundance of isotopes in a naturally-occurring element. More from Merriam-Webster on atomic weight, Britannica.com: Encyclopedia article about atomic weight. Atomic weight is the average mass of atoms of an element, calculated using the relative abundance of isotopes in a naturally-occurring element. Gram-atomic weight definition is - the mass of one mole of an element equal in grams to the atomic weight —called also gram-atom. Atomic Weight. What does atomic weight mean in finance? atomic weight - WordReference English dictionary, questions, discussion and forums. Atomic weight definition is - the mass of one atom of an element; specifically : the average mass of an atom of an element as it occurs in nature that is expressed in atomic mass units. A quality in natural bodies, by which they tend towards the centre of the earth. It is the weighted average of the masses of naturally-occurring isotopes. Abbreviated wt . What Is It Based On? where p i is the percentage or relative abundance of an isotope i of atomic mass m i . ‘The sum of the atomic mass of the protons and neutrons determines the atomic mass or atomic weight of the nucleus.’ ‘Hydrogen is the lightest element, so it provides a convenient unit for measuring the relative atomic weights of the other elements.’ ‘It has an atomic number of 101 and an approximate atomic weight of 258.’ What does atomic weight mean? The term "atomic weight" has been in use since 1808, so most people don't really care about the issues, but to reduce confusion, atomic weight is more commonly known now as relative atomic mass. She has taught science courses at the high school, college, and graduate levels. It is the ratio of the average mass per atom of an element from a given sample to 1/12 the mass of a carbon-12 atom. (See also Tables of Weights and Measures in the Appendix.) atomic number Chemical abbreviation atomic weight. The atomic weight of an element having more than one principal isotope is calculated both from the atomic masses of the isotopes and from the relative abundance of each isotope in nature. Therefore it is determined by the mass number (number of protons and neutrons). ’Atomic weight’: The name, its … wt. Delivered to your inbox! Prior to 1961, a unit of atomic weight was based on 1/16th (0.0625) of the weight of an oxygen atom. The periodic table of elements shows the atomic weight on the upper right. The picture below shows an example of Hydrogen and Sodium atoms. WEIGHT. Meaning of atomic weight. Conventional Atomic Weights and "Intervals" SI Definition of the Mole; Contributors and Attributions; There are 21 elements with only one isotope, so all their atoms have identical masses. ¹. The formula of atomic weight can be formulated based on the above definition. Cite as: IUPAC. The Atomic weight is defined as the average atomic mass of … 1. 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