The outer energy shells in the group 18 elements, called the noble gases, have a complete octet of ns2np6, where n is the highest energy level. The only exception is helium, which has an outer energy shell of 1s2.
This is the noble gases familiy.
Elements react with other elements based on the number of electrons in their outer shell, also known as valence electrons. Elements are most stable when their outer shell is full, so they will either gain, lose, or share electrons in order to achieve a full outer shell.
The highest level. Or the outer, valence shell.
Elements in the same family (or group) have the same amount of electrons in their outer shell. For Example, all elements in Group 1 have 1 electron in their outer shells.
In a group, elements have the same number of outer shell electrons, which corresponds to the group number. For example, elements in Group 1 have 1 outer shell electron, elements in Group 2 have 2 outer shell electrons, and so on. This pattern helps determine the reactivity and chemical properties of elements within the same group.
The element in the periodic table that has 4 electrons in its outer energy shell and the lowest atomic mass in its family is carbon (C). Carbon belongs to Group 14 of the periodic table, which is also known as the carbon family. With an atomic number of 6, it has the lowest atomic mass among its group, which includes elements like silicon and germanium.
The ground state of Oxygen contains only eight electrons in only the first two energy levels.
The outer or valence shell
In a neutral carbon atom, there will be 4 electrons in the outer most valence shell.
Such atoms belong to a group in the periodic table of elements.
All these elements have six electrons in the outer shell.
The valence shell (outermost energy level) of a noble gas is filled in ... ns2 np6 electron configuration except helium where it is 1s2.