A gaseous sample of an element is subjected to photoelectron spectroscopy, producing the following peaks (listed from highest to lowest binding energy):
Binding energy (MJ mol⁻¹) Relative peak height
1. 2610 2
2. 580 2
3. 410 6
4. 100 2
5. 35 2
Which element is most consistent with this spectrum?
a) Aluminum, Z=13
b) Silicon, Z=14
c) Phosphorus, Z=15
d) Argon, Z=18