Identify the element of Period 2 which has the following successive ionization energies, in kJ/mol.
A) Li
B) B
C) O
D) Ne
E) None of these choices is correct.

Question

Identify the element of Period 2 which has the following successive ionization energies, in kJ/mol. 
A) Li 
B) B 
C) O 
D) Ne 
E) None of these choices is correct.

Quizplus · Accepted Answer

The first ionization energy of oxygen is relatively high at 1314 kJ/mol, suggesting that it has a small atomic radius and a high effective nuclear charge. The second ionization energy is much higher at 3388 kJ/mol, indicating that it is difficult to remove a second electron from an oxygen ion. This is because a second electron would be taken from a noble gas configuration, which requires a large input of energy. The third ionization energy is even higher at 5300 kJ/mol, indicating that it is even more difficult to remove a third electron. This suggests that oxygen is a member of group 16 and has 6 valence electrons. Thus, the element with these successive ionization energies must be oxygen.

Identify the Element of Period 2 Which Has the Following