The atomic number of any carbon isotope is 6, the number of protons in the nucleus of any carbon atom, irrespective of its mass number.
All atomic masses are determined by comparing them to the mass of an atom of carbon12. One atomic mass unit equals one twelfth the mass of an atom of carbon12. That's why its called relativeatomic mass.
Carbon-12 (12C) is used as the standard in the relative scale for atomic masses, and its assigned atomic mass is 12 atomic mass units.
Mass number minus the atomic number equals the number of neutrons. Mass number is the number of particles in an atom that have significant mass. Electrons are assigned a value of 0 since the mass is so much smaller than protons and neutrons. Protons and neutrons are similar in mass and are assigned mass number of 1. The formula for calculating atomic mass atomic mass = # protons + # neutrons.
Carbon's atomic mass is ~12.0107. All of those decimals at the end tell us that there is more than one isotope of carbon. If you round the number, you will find the most common isotope of carbon. (Carbon12)IUPAC recommend in this case the expression atomic weight, not atomic mass.The atomic weight of carbon (IUPAC Table, 2009) is [12,0096; 12,0116]. This mean that the atomic weight is variable between the above mentioned limits, depending on the type of the sample.
hydrogen
All atomic masses are determined by comparing them to the mass of an atom of carbon12. One atomic mass unit equals one twelfth the mass of an atom of carbon12. That's why its called relativeatomic mass.
Carbon-12 (12C) is used as the standard in the relative scale for atomic masses, and its assigned atomic mass is 12 atomic mass units.
Mass number minus the atomic number equals the number of neutrons. Mass number is the number of particles in an atom that have significant mass. Electrons are assigned a value of 0 since the mass is so much smaller than protons and neutrons. Protons and neutrons are similar in mass and are assigned mass number of 1. The formula for calculating atomic mass atomic mass = # protons + # neutrons.
hydrogen
Hydrogen.
Carbon's atomic mass is ~12.0107. All of those decimals at the end tell us that there is more than one isotope of carbon. If you round the number, you will find the most common isotope of carbon. (Carbon12)IUPAC recommend in this case the expression atomic weight, not atomic mass.The atomic weight of carbon (IUPAC Table, 2009) is [12,0096; 12,0116]. This mean that the atomic weight is variable between the above mentioned limits, depending on the type of the sample.
One twelfth (1/12) the mass of a carbon-12 atom is one atomic mass unit (amu, or just u).
The atomic mass of an element is the average mass of its isotopes, taking into account their abundance in nature. It is typically listed on the periodic table below the element's symbol.
The Hydrogen atom. Beware, Hydrogen has an atomic mass based on one proton, as it doesn't have a neutron. So Helium has a mass of four times Hydrogen.
The carbon-12 atom is assigned a relative mass of exactly 12 atomic mass units (amu). This is used as the reference point for measuring the atomic masses of other elements on the periodic table.
Atomic number (protons) and atomic mass (not to be confused with atomic weight, even if the difference is slight)
Atomic mass is not a measure assigned to gross mass such as grams, kilograms, pounds, stones, tons etc.Atomic mass of an element is determined by the number of protons there are in the nucleus of that element.The amu (atomic mass unit) is standardized as 1/12 of the mass of an atom of Carbon