Question

Atomic mass is calculated by _____. subtracting protons from neutrons averaging the mass of isotopes adding protons and neutrons subtracting neutrons from protons

Answer 1

Atomic mass is calculated by taking the weighted average of the mass of an element's isotopes, factoring in each isotope's abundance and mass number. The mass number is the sum of protons and neutrons whereas the atomic mass reflects isotopic mix and abundance.

Step-by-step explanation:

Atomic mass is calculated by averaging the mass of isotopes.

The atomic mass, or average mass, of an element is calculated using the relative abundances or the fraction of each isotope within the natural abundance, multiplied by the mass number of that isotope. This calculation is known as a weighted average. So in essence, atomic mass equals f1M1 + f2M2 + f3M3 + ... where f represents the fractional abundance and M represents the mass number of an isotope.

The mass number (A) itself is the sum of the number of protons and neutrons in an atom's nucleus. This can be confusing because the atomic mass also takes into consideration the mix of an element's naturally occurring isotopes along with their abundances and individual masses, which often results in a number that contains a fraction, rather than being a whole number like the mass number.

Answer 2

Atomic mass is calculated by adding protons and neutrons.

Step-by-step explanation:

Atomic mass is the sum of protons and neutrons in an atomic nucleus. For example, the element Oxygen has 8 protons (derived from the atomic number) and 8 neutrons (derived from subtracting the amount of protons from the atomic mass).

We can craft an equation to show the relationship between these variables.

M - N = P, where M = Mass, N = Neutrons, and P = Protons

This equation can be rearranged to show the relationship between the neutrons and protons leading to the atomic mass. Simply add N to both sides of the equation.

M = N + P

This shows that atomic mass is equivalent to the sum of protons and neutrons in an atom's nucleus.