Question

1. indicate the bond type based on the change in electronegativity or types of elements.

0 - 0.4

0.4 < x < 1.7

metal + nonmetal

Explanation:

1. For electronegativity difference $0-0.4$, the bond has negligible polarity, so it is nonpolar covalent, formed between identical or very similar nonmetals.
2. For electronegativity difference $0.4 < x < 1.7$, the bond has moderate polarity, so it is polar covalent, formed between different nonmetals or some metal-nonmetal pairs with small differences.
3. For a metal + nonmetal pair (with electronegativity difference typically $\geq1.7$), electrons are transferred, forming an ionic bond.

Answer:

$0-0.4$: Nonpolar covalent bond
$0.4 < x < 1.7$: Polar covalent bond
metal + nonmetal: Ionic bond