Why does the second ionization energy of beryllium is less than that of carbon....plz explain...
Answers
Answer:
To reach the second ionization potential we remove a second electron from an already ionized element
M+1⟶M+2
Here are the electron configurations for the singly charged ions in your question, along with their second ionization potentials (kJ/mol)
Li+1Be+1B+11s2 1s2 2s1 1s2 2s2 7297 1757 2426
We see that both Li+1 and B+1 have completely filled shells, the stable "inert gas" configuration. We would expect it to be difficult to remove one electron from these two ions and destroy this stable configuration. Further, we would expect removal of one electron from Li+1 to be more difficult than from B+1 because in the former case we are removing a 1s electron which is closer to the nucleus than the 2s electron in the case of B+1. On the other hand, if Be+1 loses one electron it will have a 1s2 electron configuration and achieve a stable "inert gas" configuration. This should make it much easier to remove one electron from Be+1 than from the other two ions.
Answer:
because the increase of nuclear charge due to addition of electron now it is unstable and after second ionisation it becomes more stable.