Assertion: rutherfordium's electron | /r/HasProperty | added
Facets:
Source sentences:
text: The gist is that the energy levels of 4s and 3d are so similar in an innocent case such as argon that depending on how many protons and additional electrons are added a different orbital may be the one lower in energy and leading to the more stable electronic configuration.
text: Thus, for iron the 4s level is filled first, before an additional six d electrons are added.