Hint: Carbon-12 is the more abundant of the two stable isotopes of carbon (the other is carbon-13), accounting for $98.93\%$ of the element. The triple-alpha mechanism, which creates it in stars, is responsible for its abundance. Carbon-12 is particularly important because it serves as the reference point for determining the atomic masses of all nuclides; the atomic mass is, by definition, precisely 12 daltons. Carbon-12 has six protons, six neutrons, and six electrons.
Complete answer:
Carbon-12 is the more abundant of the two stable isotopes of carbon (the other is carbon-13), accounting for $98.93\%$ of the element. The triple-alpha mechanism, which creates it in stars, is responsible for its abundance. Carbon-12 is particularly important because it serves as the reference point for determining the atomic masses of all nuclides; the atomic mass is, by definition, precisely 12 daltons. Carbon-12 has six protons, six neutrons, and six electrons.
The mass of an atom is its atomic mass. At rest, 1 dalton equals 12 times the mass of a single carbon-12 atom. The nucleus' protons and neutrons account for almost half of an atom's overall mass, with electrons and nuclear binding energy playing a minor role. As a result, when calculated in daltons, the numeric value of the atomic mass is almost equal to the mass quantity.
Since the chemical atomic weights of carbon 12 are almost equal to those of the natural mix of oxygen, it was selected as the standard. Since no other nuclide has an identical whole-number mass on this scale except carbon-12. Six protons, six neutrons, and six electrons make up carbon-12.
Note:
Carbon-12 is the more abundant of the two stable isotopes of carbon (the other is carbon-13), accounting for $98.93\%$ of the element. The triple-alpha mechanism, which creates it in stars, is responsible for its abundance. Carbon-12 is particularly important because it serves as the reference point for determining the atomic masses of all nuclides; the atomic mass is, by definition, precisely 12 daltons. Carbon-12 has six protons, six neutrons, and six electrons.
Carbon-12, the nucleus of which contains six protons and six neutrons, is indeed the most prevalent stable isotope of carbon, constituting nearly 99% of naturally occurring carbon. Its significance lies not only in its abundance but also in its pivotal role as the standard for atomic masses. The determination of atomic masses for all nuclides is based on this isotope, as its atomic mass is defined as precisely 12 daltons.
The triple-alpha process, occurring within stars during their evolution, synthesizes carbon-12. This mechanism involves the fusion of three alpha particles (helium nuclei) to form carbon-12, a critical step in stellar nucleosynthesis.
Understanding the concept of atomic mass is crucial here. An atom's mass, measured in daltons, largely corresponds to its atomic mass at rest. For carbon-12, one dalton is defined as 1/12th the mass of a single atom of this isotope at rest. Approximately half of an atom's mass is concentrated within its nucleus, primarily attributed to the protons and neutrons. The remaining mass includes electrons and nuclear binding energy, which contribute minimally to the overall mass.
The selection of carbon-12 as the reference for atomic weights stems from its similarity in chemical atomic weights to natural oxygen mixtures. Since no other nuclide aligns perfectly with a whole-number mass on this scale, carbon-12 stands as the sole isotope that uniquely fits this criterion.
This is crucial for standardization and scientific measurements, ensuring consistency in calculations and understanding across different contexts. The atomic structure of carbon-12, comprising six protons, six neutrons, and six electrons, further solidifies its significance as a foundational element in the field of atomic and molecular studies.
Let's break down the concepts used:
- Isotope: Different forms of an element with the same number of protons but varying numbers of neutrons.
- Atomic Mass: The mass of an atom, mainly concentrated in the nucleus due to protons and neutrons, with electrons contributing minimally.
- Triple-Alpha Process: A stellar nuclear fusion process where three alpha particles (helium nuclei) combine to form carbon-12.
- Standard for Atomic Mass: Carbon-12 serves as the reference point for determining the atomic masses of all nuclides.
- Dalton: A unit used to measure atomic mass. 1 dalton equals 1/12th the mass of a carbon-12 atom at rest.
- Nucleosynthesis: The process by which heavier elements are synthesized from lighter elements within stars.
- Chemical Atomic Weights: Comparison of the average atomic masses of elements based on their natural abundances.
These concepts underpin our understanding of atomic structure, isotopes, and the fundamental units used in atomic measurements.
