MLA Citations
http://www.shodor.org/unchem/basic/atom/index.html
http://periodictable.com/Properties/A/ElectronConfigurationString.al.htmlhttp://www.rsc.org/chemsoc/visualelements/pages/data/intro_groupviii_data.html
http://periodictable.com/Properties/A/ElectronConfigurationString.al.htmlhttp://www.rsc.org/chemsoc/visualelements/pages/data/intro_groupviii_data.html