🤓 Based on our data, we think this question is relevant for Professor Gerold's class at CSU.
One bit of evidence that the quantum mechanical model is “correct” lies in the magnetic properties of matter. Atoms with unpaired electrons are attracted by magnetic fields and thus are said to exhibit paramagnetism. The degree to which this effect is observed is directly related to the number of unpaired electrons present in the atom. Consider the ground-state electron configurations for Li, N, Ni, Te, Ba, and Hg. Which of these atoms would be expected to be paramagnetic, and how many unpaired electrons are present in each paramagnetic atom?
We first need to determine the ground-state electron configuration of each given element and then construct orbital diagrams to determine which among them are paramagnetic and if so, how many unpaired electrons are present.
For Li: The atomic number of lithium is 3, which means the ground-state element has 3 electrons.
The noble gas before lithium is He, which accounts for 2 electrons and whose electron configuration ends at 1s2. From 1s2, start with the next subshell until we have a total 3 electrons: 2s1. The shorthand electron configuration for Li is [He]2s1.