Question

binding energy (mj/mol)
the photoelectron spectrum for an unknown element is shown above.
(a) based on the photoelectron spectrum, identify the unknown element and write its electron configuration.
note on your ap exam, you will handwrite your responses to free - response questions in a test booklet
the element is aluminum and its electron configuration is 1s2,2s2,2p6,3s2,3p1
(b) consider the element in the periodic table that is directly to the right of the element identified in part (a). would the 1s peak of this element appear to the left of, the right of, or in the same position as the 1s peak of the element in part (a)? explain your reasoning.

Explanation:

The element to the right of aluminum in the periodic table is silicon. The 1s peak of silicon would appear to the left of the 1s peak of aluminum. This is because silicon has a greater nuclear charge (14 protons) compared to aluminum (13 protons). The 1s electrons in silicon are more strongly attracted to the nucleus due to the higher - positive charge, resulting in a higher binding energy. In a photoelectron spectrum, higher binding energy corresponds to a peak at a higher energy value (to the left on the x - axis which represents binding energy).

Answer:

The 1s peak of the element (silicon) would appear to the left of the 1s peak of aluminum because silicon has a greater nuclear charge, leading to a higher binding energy for its 1s electrons.