The atomic mass of an element is
A. the sum of the protons and electrons in one atom of the element.
B. twice the number of protons in one atom of the element.
C. a ratio based on the mass of a carbon-12 atom.
D. a weighted average of the masses of an element’s isotopes. ****
wait which one is it then??
You guys/gals really need help. The initial answer given is the correct answer. That is D.
You're correct
thank you so much Starkiller !!
The correct answer is D. The atomic mass of an element is a weighted average of the masses of an element's isotopes.
To understand this, we need to first understand what isotopes are. Isotopes are variants of an element that have the same number of protons but different numbers of neutrons. Since the number of neutrons can vary, isotopes of an element have different mass numbers.
The atomic mass of an element takes into account the mass and abundance of each isotope of that element. The atomic mass of any given isotope is determined by multiplying the mass of the isotope by its abundance (in decimal form), and then summing up the results for all the isotopes of that element.
For example, let's say we have an element X with two isotopes. Isotope X-1 has a mass of 10 amu (atomic mass units) and an abundance of 75%, while isotope X-2 has a mass of 12 amu and an abundance of 25%. To calculate the atomic mass of element X, we would calculate:
(10 amu x 0.75) + (12 amu x 0.25) = 7.5 amu + 3 amu = 10.5 amu
This means that the atomic mass of element X is 10.5 amu.
So, to get the atomic mass of an element, we need to know the masses and abundances of all its isotopes, and then perform the necessary calculations. The answer choice D correctly states that the atomic mass is a weighted average of the masses of an element's isotopes.