Answer: The compound formed between nitrogen (N) and nitrogen (N) a polar covalent bond because there is less than a 0.4 difference in electronegativity between the atoms.
Explanation:
If electronegativity difference between two atoms is less than 0.4 then bond formed is a pure covalent bond.
If electronegativity difference between two atoms is between 0.4 to 1.8 then bond formed is a polar covalent bond.
If electronegativity difference between two atoms is greater than 1.8 then bond formed is an ionic bond.
The electronegativity value of a nitrogen atom is 3.04. Hence, the electronegativity difference of 
molecule is as follows.
As the electronegativity difference is 0 which is less than 0.4.
Hence, we can conclude that the compound formed between nitrogen (N) and nitrogen (N) a polar covalent bond because there is less than a 0.4 difference in electronegativity between the atoms.
Answer:
SF2 > H2O > PBr3 > NCl3
Explanation:
Compare the electronegativity values for the atoms and classify the nature of the bonding based on the electronegativity difference.
P has an electronegativity of 2.1, while Br has an electronegativity of 2.96. The difference is 0.86, indicating that these atoms will form covalent bonds.
S has an electronegativity of 2.58 while F has an electronegativity of 4.0. The difference is 1.42, indicating that these atoms will form polar covalent bonds.
O has an electronegativity of 3.5 while H has an electronegativity of 2.1. The difference is 1.4, indicating that these atoms will form polar covalent bonds.
N has an electronegativity of 3.04, whereas Cl has an electronegativity of 3.5. This difference of 0.46 indicates that these atoms will form covalent bonds.
We know that the greater the electronegativity, the higher the polarity. In decreasing order of polarity, we have:
SF2 > H2O > PBr3 > NCl3
In ionic bonds, one atom gives one or more electrons to another atom so both can get closer to 8 valence electrons. Example: In potassium chloride (KCl), Potassium gives up one valence electron to chlorine, so that the outer shell of potassium has 8 valence electrons. This happens only between metals and nonmetals.
In covalent bonds, atoms share their electrons to reach 8 valence electrons. Example: In water (H2O), Oxygen shares one valence electron with one atom of hydrogen, and another valence electron with another atom of hydrogen. Oxygen now has 8 (4 unshared + 2 of its own + 1 from hydrogen + 1 from hydrogen), and each hydrogen has 2 valence electrons: one of its own and one from oxygen [ note that hydrogen only needs 2 valence electrons to be complete instead of 8].
In metallic bonds between metals, the valence electrons move much more freely than in other bonds. This free characteristic makes metals how they are: ductile, malleable, sectile, conductive, etc.
