yes
If the atom is chemically stable it doesnt need to bond, it is chemically stable when the outermost level is completely full of electrons
8 electrons
Generally speaking, it would be 8 electrons, but there are many exceptions.
8 are traditionally needed in the valence shell.
Helium is stable with 2 valence electrons. It has a full outer electron shell, making it chemically inert and stable.
filled with electrons
In covalent compounds, atoms become chemically stable by sharing electrons with each other to fill their outermost energy levels. By sharing electrons, atoms can achieve a full outer electron shell, which is typically 8 electrons for most elements (except for hydrogen and helium which need 2 electrons).
Most atoms are chemically stable when they have eight electrons in their outer energy level, a concept known as the octet rule. This applies to many elements, especially those in the second and third periods of the periodic table. However, some elements, like helium, are stable with just two electrons in their outer shell. Thus, while eight is the general requirement, there are exceptions based on specific elements.
Gases with eight valence electrons.
Just one. To become stable, it needs eight electrons; a full outer shell.
No, sulfur has only 6 valence electrons. Atoms with 8 valence electrons are most stable and generally chemically inert.
The number of electrons must be eight.