Table of Contents
Why is the atomic mass of carbon-12.011 and not just 12?
Although carbon‐12 weighs exactly 12 amu, the periodic table reports that the mass is 12.011 because we are taking into consideration the abundances and masses of the other two carbon isotopes (carbon‐13 and carbon‐ 14).
Why is the mass of a carbon-12 atom exactly 12.0 U?
Its mass is exactly 12 u because of the definition of the “unified atomic mass unit” or u as one-twelfth of that isotope carbon. That mass corresponds to 1.660539040⋅10−24g , thus the mass in grams of a single atom of isotope 12 is 12.000000⋅1.660539040⋅10−24g=19,926468⋅10−24grams .
Why is the atomic mass of carbon listed as 12.01 amu in the table of element?
On the periodic table the mass of carbon is reported as 12.01 amu. This is the average atomic mass of carbon. The natural abundances of 14C, 10C and 11C are so low that most mass spectrometers cannot detect the effect these isotopes have on the average mass.
What is the mass of carbon-12?
Click symbol for equation | |
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molar mass of carbon-12 | |
Numerical value | 11.999 999 9958 x 10-3 kg mol-1 |
Standard uncertainty | 0.000 000 0036 x 10-3 kg mol-1 |
Relative standard uncertainty | 3.0 x 10-10 |
Why is carbon-12 a whole number?
Atomic mass is never an integer number for several reasons: The atomic mass reported on a periodic table is the weighted average of all the naturally occuring isotopes. The mass of an individual atom in atomic mass units is the mass relative to carbon-12. Only carbon-12 has a mass exactly equal to itself.
What is the mass of 1 atom of carbon-12 in Gram?
Mass of one mole of C12 = 12 g. so mass of 1 atom of C12 = 1.9927e-23 g.
What is the average atomic mass of a carbon atom?
This is the average atomic mass of carbon. No single carbon atom has a mass of 12.01 amu, but in a handful of C atoms the average mass of the carbon atoms is 12.01 amu. Why 12.01 amu?
What is the mass of 12C (carbon twelve)?
Atomic mass is based on a relative scale and the mass of12C (carbon twelve) is defined as 12 amu. Why do we specify 12C? We do not simply state the themass of a C atom is 12 amu because elements exist as a variety ofisotopes.
What is the mass mass of a C atom?
mass of a C atom is 12 amu because elements exist as a variety of
What is the atomic mass of hydrogen on carbon-12 scale?
For e.g. – (a) atomic mass of nitrogen is 14 u i.e. one atom of nitrogen is 14 times heavier than 1/12 of a carbon-12 atom. (b) Hydrogen atom is only 0.0840 times heavier than C-12 atoms.That means, on carbon-12 scale, atomic mass of hydrogen = 0.0840 × 12.00 u = 1.008 u.