because they have completely filled orbitals
they are generally chemically inert
Sulfur needs to gain 2 electrons to have the electon configuration of Argon
[Ar] 4s23d6
Iron 2 is Fe 2+ and has electron configuration [Ar] s1d5 Iron 3 is Fe 3+ and has electron configuration [Ar] d5
Iron's atomic number is 26. Thus it has 26 protons and 26 electrons. The electronic configuration for the first 26 electrons, and so therefore iron, is Fe 1s2 2s2 2p6 3s2 3p6 4s2 3d6. The shorthand electron configuration is Fe [Ar] 4s2 3d6.
Iron (Fe)
Fe, or iron, has the atomic number of 26. Its full orbital diagram is 1s2 2s2 2p6 3s2 3p6 4s2 3d6.
Molybdenum's electon configuration is [Kr] 5s1 4d5 this is because all elements want to be half-full or full. so the 2nd electron in the 5s2 moves to make the 4d4 complete so it turns to 5s1 4d5....making Mo half-full and stable.
The element silicon (atomic number 14) has the following electron configuration :- Full configuration: 1s2 2s2 2p6 3s2 3p2- Compressed (without all standard script numbers): 1s2 2s2p6 3s2p2- Noble Gas form : [Ne] 3s2 3p2 / [Ne] 3s2p2 (this works because [Ne] symbolizes the electronic configuration of Neon, which is 1s2 2s2 2p6. When added to 3s2p2, it is equivalent to the full electron configuration of Silicon, when neutral.)The electon configuration of silicon is 1s22s22p63s23p2. The abbrieviated electron configuration is [Ne]3s23p2.
If you meant the Fe in the transition elements, then it means iron. Iron is represented by Fe because iron's Latin name is ferrum.
Phosphorus To determine an element from its electron configuration, simply add up the superscript numbers (those are the numbers of electrons in each sublevel): 1s22s22p63s23p3: 2+2+6+2+3=15, and find the element with the matching atomic number*. In this case, Phosphorus. *Note: This method is not correct if the electron configuration of an ion is given, as the number of electrons in an ion does not match its atomic number.