A covalent bond is formed when sharing electrons.
Aufbau theorized that electrons travelled in energy shells, hence the Aufbau diagram...
electrons are arranged in energy levels, or shells, around the nucleus of an atom.
Energy levels or energy shells or orbits
The electrons in actinium are disposed on seven energy levels.
A shell surrounding the nucleus of an atom containing electrons.
This is the valence shell and is involved in bonding e.g. the sharing or loss of electrons to form a molecule or giant structure. Inner shells do not take part in bonding though their shielding effect and repulsion does affect the loss and gain of electrons from this shell.
The electrons in actinium are disposed on seven energy levels.
Sulfur contains atoms in three energy shells.
No. Electrons gain energy as they move up the chain, i.e. in more outer shells.
Tungsten atoms contain six energy levels (shells). The outermost energy level is the sixth energy level. It has two electrons in the 6s sublevel.
Energy level or energy shells are the specific locations where the electrons revolve around the nucleus. Each energy level is associated with specific amount of energy. The outermost is most important because it is the one which accepts the electrons from outside the atom or looses the electron.
They have filled valence shells. Atoms undergo chemical bonding in order to have filled valence shells by sharing electrons or transferring electrons. Because the noble gases already have filled valence shells, they have no need to react with other elements.