Atomic mass unit (amu) ... One atomic mass unit is equal to the mass of one proton ... You will find the mass number by rounding the atomic mass to the nearest whole number

Back to Main Page ... ; Parentheses Indicate Mass of Most Stable Isotope ... Periodic Table with Atomic Mass at Chemical Elements.com

atomic mass n. The mass of an atom, usually expressed in atomic mass units. ... Some textbooks and other sources use the term atomic weight instead of atomic mass.

Yes, but we don't normally use those units for measuring the mass of an atom. It's much more convenient to use something called the atomic mass unit, or amu.

In the modern periodic table, the elements are actually arranged in order of increasing atomic number--that's the number of protons in one atom of a particular element.

Atomic Mass definition, as used in chemistry and other physical sciences. ... Definition: Atomic mass or atomic weight is the average mass of atoms of an element, calculated using the relative

How to Calculate Atomic Mass. The mass of a single atom is so small that a unit of measurement has been created to describe it--the atomic mass unit (amu). ... An atomic mass unit, also called a

Atomic weight (symbol: A r ) is a dimensionless physical quantity, the ratio of the average mass of atoms of an element (from a given source) to 1/12 of the mass of an atom of carbon-12. The term is usually used, without further qualification, to refer to the standard atomic weights...

When the accurate atomic mass of an atom is rounded to a whole number, it equals the mass number...

Britannica online encyclopedia article on atomic mass (physics), the quantity of matter contained in an atom of an element. ... For a definition of "atomic mass (physics)", visit Merriam-Webster.