Four
Each sodium atom will lose one electron to achieve a complete octet in its outer shell, as the octet rule dictates atoms will gain or lose electrons to achieve a stable electron configuration with 8 electrons in the outer shell.
carbon has 4 valence electrons and can form a maximum 4 bonds with other atoms.
Oxygen needs to gain 2 electrons to reach an octet, as it has 6 valence electrons in its outer shell and requires a total of 8 electrons to have a stable octet configuration.
You can see this happen in the F2 molecule. Each fluorine atom shares a valence electron with the other fluorine atom. So there is just one covalent bond.
Oxygen typically forms 2 shared electrons when it bonds with other atoms, such as in H2O (water) or O2 (oxygen gas). These shared electrons help oxygen satisfy the octet rule by achieving a full outer shell of 8 electrons.
Fluorine needs one additional electron to satisfy the octet rule, giving it a total of 8 valence electrons and achieving a stable electron configuration.
In a Lewis dot structure of carbon, four electrons are needed to fill its valence shell, which can accommodate a total of eight electrons. Carbon typically forms four single bonds in its compounds to satisfy the octet rule.
Each sodium atom will lose one electron to achieve a complete octet in its outer shell, as the octet rule dictates atoms will gain or lose electrons to achieve a stable electron configuration with 8 electrons in the outer shell.
Strontium typically loses 2 electrons to satisfy the octet rule. Since strontium is in group 2 of the periodic table, it has 2 valence electrons. By losing these two electrons, it attains a stable electron configuration similar to a noble gas.
Carbon has four electrons in its outer shell and needs four more electrons to complete its octet.
Seven electrons should be added to attain the higher noble gas configuration.
Beryllium will lose 2 electrons to satisfy the octet rule (to fill its outer shell).
Silicon, like carbon, has four valance electrons, and needs another four to have a stable octet.
A potassium atom has 1 electron in its outer shell. In order to satisfy the octet rule, it needs to donate 7 electrons to another atom to reach a stable configuration with a full outer shell.
In propane (C₃H₈), the central carbon atom is bonded to two other carbon atoms and two hydrogen atoms. Each carbon atom forms four covalent bonds to achieve a complete octet. Therefore, the central carbon atom uses four of its electrons to form these bonds, ensuring its octet is complete.
It makes two covalent bonds which completes its octet.
8: that's the meaning of "octet".