3 electrons
Oxygen should gain 2 electrons to achieve noble gas configuration
Chlorine need one extra negatively charged electron to be a noble gas.
Krypton is a noble gas and need not lose electrons. It is already stable.
Nitrogen has to gain three electrons
A species (element, cation or anion) should have eight valence electrons to have a noble gas electronic configuration. However element upto atomic number 4 may have 2 valence electrons and attain the electronic configuration of helium noble gas.
Oxygen should gain 2 electrons to achieve noble gas configuration
Chlorine need one extra negatively charged electron to be a noble gas.
Krypton is a noble gas and need not lose electrons. It is already stable.
They should gain 2 electrons to attain noble gas electronic configuration. (it doesn't become a noble gas as the number of protons are not same)
4 but it will need energy, so carbon gain 4 electrons to achieve a noble gas configuration.
three
Nitrogen has to gain three electrons
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.
A species (element, cation or anion) should have eight valence electrons to have a noble gas electronic configuration. However element upto atomic number 4 may have 2 valence electrons and attain the electronic configuration of helium noble gas.
It should loose 2 electrons to become a noble gas.
There are six electrons in two shells.In order to stable carbon, it take electrons from nearest noble gas to stable the carbon.It order to stable carbon it gain -4 electrons from the nearest noble gas Neon.
4