Answer:
First statement is true:
- <u><em>NH₄ would be expected to have polar covalent bonds with a partial positive charges on the H atoms.</em></u>
Explanation:
Nitrogen (N) and hydrogen (H) are two nonmetals; thus, it should be a hint to assert that they form a covalent bond.
The difference in <em>electronegativities</em> between<em> N</em> and <em>H </em>is <em>3.0</em> - <em>2.1</em> = 0.9.
That makes that the bonds be <em>polar</em>. Ions are not formed because to transfer the electrons from one atom to the other (to form ionic bonds) requires an electronegativity difference greater than about 1.7.
Since N is more electronegative than H, in the molecule <em>NH₄</em>, each N atom will pull the electron density toward itself acquiring a partial negative charge and leaving H atoms with a partial positive charge.
Thus, each NH bond is<em> polar covalent with a partial positive charge on the H atoms</em> (first statement from the choices).