Question

1. the ionization energies of a given atom are ie1 = 5.139 kj/mol, ie2 = 47.286 kj/mol., ie3 = 71.64 kj/mol. predict the valence electron configuration for the atom, and explain your reasoning.

2

Explanation:

Ionization energy ($IE$) is the energy required to remove an electron from an atom. A large jump in $IE$ occurs when a core (non - valence) electron is removed. Here, $IE_1 = 5.139\ kJ/mol$ and $IE_2=47.286\ kJ/mol$. The large increase from $IE_1$ to $IE_2$ indicates that after removing the first electron (valence electron), the second electron is a core electron. So, the atom has 1 valence electron. The general valence electron configuration for an element with 1 valence electron in the $s$ - block is $ns^1$.

Answer:

The valence electron configuration is $ns^1$. The reasoning is that there is a large jump from $IE_1$ (removing a valence electron) to $IE_2$ (removing a core electron), indicating 1 valence electron, which follows the $ns^1$ configuration pattern.