Question

which of the following statements best describes the pattern differences between elements that typically form covalent bonds versus those that form ionic bonds?
elements that form covalent bonds are generally metals, while those that form ionic bonds are nonmetals.
elements that bond covalently usually have high melting and boiling points, while those that bond ionically have low melting and boiling points.
covalent bonds typically occur between elements with similar electronegativities, while ionic bonds form between elements with significantly different electronegativities.
ionic bonds involve the sharing of electrons between atoms, whereas covalent bonds involve the transfer of electrons.

Explanation:

• Let's analyze each option:
• Option 1: Elements that form covalent bonds are non - metals (sharing electrons), and ionic bonds are between metals and non - metals (electron transfer). So this option is wrong.
• Option 2: Ionic compounds have high melting and boiling points (strong electrostatic forces), while many covalent compounds (except network covalent like diamond) have low melting and boiling points. So this option is wrong.
• Option 3: Covalent bonds form when electronegativity difference ($\Delta EN<1.7$) is small (similar electronegativities, sharing electrons), and ionic bonds form when $\Delta EN > 1.7$ (electron transfer). This is correct.
• Option 4: Ionic bonds involve electron transfer, and covalent bonds involve electron sharing. So this option is wrong.

Answer:

Covalent bonds typically occur between elements with similar electronegativities, while ionic bonds form between elements with significantly different electronegativities.