Ca needs to lose 2 electrons to become Ca+2
two electrons lost
2
ionic bond calcium donates 2 electrons to two chlorine atoms and both attain stable configuration
Chlorine is a non metal and it reacts by gaining electrons rather than losing inorder to attain a stable electron configuration of the noble gases.
Lithium has one valence electron. It is much easier for an atom to lose one electron than gain seven more. Lithium looses this one electron to achieve a full outer shell (the next inside shell is full).
two electrons lost
Calcium loses two electrons to obtain a noble-gas electron configuration.
Gain two electrons to have the electron configuration as Argon
true, just not for Boron witch tries to gain 6 electrons for a stable arrangement
4
It loses 2 electrons and becomes a +2 ion.
2
nitrogen should give 5 electrons (or better gain 3 electrons) to attain noble gas configuration.
aluminium should lose three electrons to attain noble gas configuration
Sulfur has six valence electrons and can therefore attain an inert gas configuration in two different ways: by accepting two electrons to attain the electron configuration of argon or donating or sharing six electrons to attain the electron configuration of neon. In combination with the much less electronegative element sodium, sulfur accepts one electron from each of two sodium atoms to form the ionic compound Na2S, but in combination with the more electronegative element fluorine, sulfur shares its six valence electrons with each of six fluorine atoms to form six polar covalent bonds with fluorine.
Krypton is a noble gas and need not lose electrons. It is already stable.
An atom of silicon needs to gain 4 electrons in its 3p sublevel to attain the noble gas electron configuration of argon, the noble gas in period 3 of the periodic table.