what is the predicted order of first ionization energies from highest to lowest for aluminum, phosphorus…
what is the predicted order of first ionization energies from highest to lowest for aluminum, phosphorus, silicon, and sulfur?\no al > p > si > s\no al > si > p > s\no s > p > si > al\no p > s > si > al
Answer
Explanation:
Step1: Recall ionization - energy trend
Ionization energy generally increases across a period from left - to - right due to increasing nuclear charge and decreasing atomic radius. However, there are some exceptions.
Step2: Analyze the positions of elements
Aluminum (Al), silicon (Si), phosphorus (P), and sulfur (S) are in the third period. Al is in group 13, Si in group 14, P in group 15, and S in group 16.
Step3: Consider the exception
The general trend would suggest an increase in ionization energy from Al to S. But phosphorus has a half - filled 3p sub - shell ($3p^3$), which gives it extra stability. So, the ionization energy of P is higher than that of S.
Answer:
P > S > Si > Al