On the ionization energy vs. atomic number graph, the peaks, which are Noble Gases, gradually get smaller. Which statement below would best explain that pattern?



A Each successive element on the peaks has fewer electrons and that would make ionization energy less.


B Each element has more electrons and they are in levels that are farther from the nucleus so it takes less energy to remove them.


C These elements are getting bigger nuclei because they have more protons. This would create a stronger pull on the electrons which would make the ionization energy less.


D All of the above

I think B is the best answer although it isn't complete. The atoms ARE getting larger, the outer electrons ARE farther away AND there are more shielding electrons between the nucleus and the outer electron so it is easier to remove the outer electron.

D All of the above

I mean, that's a pretty solid answer. Plus, it's always nice to have options, right?

The correct answer is C. These elements are getting bigger nuclei because they have more protons. This would create a stronger pull on the electrons which would make the ionization energy less.

The correct answer is C: These elements are getting bigger nuclei because they have more protons. This would create a stronger pull on the electrons which would make the ionization energy less.

To understand why this statement is true, we need to consider a few concepts related to ionization energy and atomic structure.

Ionization energy refers to the energy required to remove an electron from an atom or ion. It is a measure of how strongly an atom holds onto its electrons. Generally, atoms with smaller radii and larger nuclear charges (more protons) have higher ionization energies because the electrons are held more tightly by the stronger nuclear attraction.

Noble gases, such as helium, neon, argon, etc., are known for having full electron shells, making them stable and less likely to lose or gain electrons. On the ionization energy vs. atomic number graph, the peaks represent the noble gases. As we move across the periodic table from left to right, the atomic number (number of protons) increases, leading to larger nuclear charges.

In this context, option C explains the observed pattern correctly. With an increase in the number of protons in the nucleus, the attractive force between the positively charged protons and the negatively charged electrons becomes stronger. As a result, the electrons in the outer energy levels of the noble gases experience a greater pull from the nucleus, making it more difficult to remove an electron and therefore requiring more energy (higher ionization energy).

Options A and B are incorrect explanations. Option A states that each successive element has fewer electrons, which does not hold true for the noble gases as their electron configurations are typically filled with a stable number of electrons. Option B suggests that the increase in electrons and their distance from the nucleus leads to lower ionization energy, which is contrary to the observed trend.