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1. Because most elements exist as mixtures of several stable isotopes, the atomic mass of an element is defined as the weighted average of the masses of the isotopes. For example, naturally occurring carbon is largely a mixture of two isotopes: 98.89% 12 C (mass = 12 amu by definition) and 1.11% 13 C (mass = 13.003355 amu).
The mass of one atom is usually expressed in atomic mass units (amu), which is referred to as the atomic mass. An amu is defined as exactly 1 / 12 of the mass of a carbon-12 atom and is equal to 1.6605 × 10 −24 g. Protons are relatively heavy particles with a charge of 1+ and a mass of 1.0073 amu.
Molar mass of caffeine is 194. If it contains 28.9% of nitrogen by mass, calculate the number of nitrogen atoms in one molecule of caffeine .
A nitrogen atom with 7 protons and 8 neutrons has a mass number of 15 amu. On the periodic table, the atomic mass for nitrogen is 14.01. How is this possible?
Atomic Weights and Isotopic Compositions for Nitrogen Isotope Relative Atomic Mass Isotopic Composition Standard Atomic Weight Notes : 7 : N : 14 : 14.003 074 004 43(20)
Mar 8, 2022 · There are two steps to find the mass of the Nitrogen (N) atom. First we find the atomic mass of N from the Periodic Table. We then divide this by Avogadro's...
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Jul 29, 2021 · The average atomic mass of carbon is then calculated as (0.9889 × 12 amu) + (0.0111 × 13.003355 amu) = 12.01 amu. Carbon is predominantly 12 C, so its average atomic mass should be close to 12 amu, which is in agreement with our calculation.
