Question

The masses of all isotopes are based on a comparison to the mass of a particular isotope of ______.

Answer 1

Carbon-12.

Step-by-step explanation:

The masses of all isotopes are based on a comparison to the mass of a particular isotope of Carbon, specifically Carbon-12.

Isotopes are atoms of the same element that have different numbers of neutrons. The mass of an isotope is determined by the number of protons and neutrons it contains. To compare the masses of different isotopes, scientists use a reference isotope called Carbon-12. Carbon-12 is chosen as the reference because it is stable and has a well-defined mass.

The mass of Carbon-12 is defined as exactly 12 atomic mass units (AMU). One atomic mass unit is defined as one-twelfth the mass of a Carbon-12 atom. By comparing the masses of other isotopes to the mass of Carbon-12, scientists can determine the relative masses of these isotopes.

For example, Carbon-14 is an isotope of Carbon with 6 protons and 8 neutrons. Since Carbon-12 is the reference isotope, Carbon-14 is found to have a mass of approximately 14 atomic mass units. This means that Carbon-14 is slightly heavier than Carbon-12 due to the extra neutrons it contains.

In summary, the masses of all isotopes are based on a comparison to the mass of a particular isotope of Carbon called Carbon-12. This reference isotope allows scientists to determine the relative masses of other isotopes by comparing them to Carbon-12

Answer 2

The answer to your question is carbon. The masses of all isotopes are based on a comparison to the mass of a particular isotope of carbon123. This isotope is carbon-12, which has six protons and six neutrons in its nucleus. By definition, one atom of carbon-12 is assigned a mass of exactly 12 atomic mass units (amu), which is a unit of mass equal to one twelfth of an atom of carbon-1212. All other isotopes have their masses expressed as a fraction or a multiple of this standard unit. For example, the isotope hydrogen-1 has a mass of 1.0078 amu, which means it is slightly heavier than one twelfth of carbon-12. The isotope uranium-238 has a mass of 238.0508 amu, which means it is almost 20 times heavier than carbon-12. The reason why carbon-12 was chosen as the reference standard is because it is abundant, stable, and easy to measure3. I hope this answer helps you understand the concept of isotopes and atomic mass better.