Question

b. hydrogen and fluorine

1. which of the following combinations of elements would form the least polar bond?

a. hydrogen and phosphorus
b. hydrogen and oxygen
c. hydrogen and chlorine
d. hydrogen and nitrogen
how do electronegativity and ionization energy relate to the formation of covalent bonds between atoms?
select one correct answer in each box to complete each sentence.
covalent bonds form between atoms with (different) (similar) electronegativities. these atoms also tend to have (high) (low) ionization energies.

Explanation:

First Question (Which combination forms least polar bond)

Polarity of a covalent bond depends on the electronegativity difference between the two atoms. A smaller electronegativity difference means a less polar bond.

• Electronegativity values (approximate): H = 2.1, P = 2.1, O = 3.5, Cl = 3.0, N = 3.0.
• For option A (H and P): Electronegativity difference is \(|2.1 - 2.1| = 0\) (non - polar, or least polar as difference is smallest).
• For option B (H and O): Difference is \(|3.5 - 2.1| = 1.4\).
• For option C (H and Cl): Difference is \(|3.0 - 2.1| = 0.9\).
• For option D (H and N): Difference is \(|3.0 - 2.1| = 0.9\).

So, Hydrogen and phosphorus have the smallest electronegativity difference, forming the least polar bond.

1. Covalent bonds form between atoms with similar electronegativities. If electronegativities are very different, an ionic bond is more likely. Atoms with similar electronegativities share electrons to form covalent bonds.
2. Atoms that form covalent bonds tend to have high ionization energies. High ionization energy means it is difficult for the atom to lose electrons (so they prefer to share electrons rather than lose or gain them to form ions).

Answer:

A. Hydrogen and phosphorus

Second Question (Relating electronegativity and ionization energy to covalent bonds)