Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

-The atomic masses given in the periodic table of the elements are rarely whole

ID: 104421 • Letter: #

Question

-The atomic masses given in the periodic table of the elements are rarely whole numbers, even though each nucleus contains a whole number of protons and neutrons. What is one reason for this?

The masses shown represent the weighted average of the masses of the different isotopes

Even though one atom has a whole number of protons and neutrons, there is not a whole number of atoms in a mole

The masses will round off to whole numbers with the correct number of significant figures

The electrons have a mass that is only a fraction of the proton mass

1.

The masses shown represent the weighted average of the masses of the different isotopes

2.

Even though one atom has a whole number of protons and neutrons, there is not a whole number of atoms in a mole

3.

The masses will round off to whole numbers with the correct number of significant figures

4.

The electrons have a mass that is only a fraction of the proton mass

Explanation / Answer

atomic mass is the average mass takes over all the different isotopes of the element

All elements have one or more isotopes and due to this, there is always average takes to calculate the atomic mass

So, the atomic mass is often fractional

Answer: option 1