Questions: Understanding main-group periodic trends in ionization energy Four main-group elements a, b, c, and d are highlighted in the outline of the Periodic Table below: List these elements below by increasing ionization energy. For example, if a has the lowest ionization energy and b the next highest, then your list should start a, b, ... Important: don't try to figure out exactly which elements are marked, and then use your knowledge of the properties of each specific element. You will also be marked wrong for any answer, correct or not, that can't be determined from only the rough location of each marked element in the Periodic Table.

Solution Steps

Ionization energy generally increases across a period (left to right) and decreases down a group (top to bottom) in the periodic table. This is because atoms on the right side of the periodic table have more protons, which increases the nuclear charge and holds the electrons more tightly, making them harder to remove. Conversely, atoms lower in a group have more electron shells, which increases the distance between the nucleus and the outermost electrons, making them easier to remove.

Assume the elements a, b, c, and d are positioned as follows in the periodic table:

\[ \begin{array}{|c|c|c|c|} \hline a & b & c & d \\ \hline \end{array} \]

Given the general trend:

• Element \(a\) is the furthest left and likely has the lowest ionization energy.
• Element \(d\) is the furthest right and likely has the highest ionization energy.
• Elements \(b\) and \(c\) are in between, with \(b\) having a lower ionization energy than \(c\).

Final Answer