Question

the complete photoelectron spectrum of an element is given above. which labeled peak corresponds to the 1s electrons and why?
a peak x, because 1s electrons are the easiest to remove from the atom.
b peak x, because 1s electrons have the strongest attractions to the nucleus.
c peak y, because electrons in the 1s sublevel are the farthest from the nucleus.

Explanation:

Step1: Understand binding energy concept

Binding energy is the energy required to remove an electron from an atom. Electrons closer to the nucleus have higher binding energy as they are more strongly attracted by the nucleus.

Step2: Analyze 1s electrons' position

1s electrons are in the innermost shell, closest to the nucleus. So they have the highest binding energy among all electrons in an atom.

Step3: Match with the peak

Looking at the graph, peak X has a higher binding energy value compared to peak Y.

Answer:

B. Peak X, because 1s electrons have the strongest attractions to the nucleus.