Question

Do these look right?

What shape does an ammonia (NH3) molecule have?trigonal pyramidal

In a tetrahedral molecule, how many unshared pairs of valence electrons does the central atom have? none

In a polar bond, electrons are? completely transferred

What determines the polarity of a bond? molecular shape only

What determines the polarity of a molecule?electronegativity difference only

Answer 1

What shape does an ammonia (NH3) molecule have?trigonal pyramidal
<b>correct</b>

In a tetrahedral molecule, how many unshared pairs of valence electrons does the central atom have? none
<b>This answer is correct for AB₄ type molecules in which the central atom has a valence of 4 and each bond has a element (in this case B) attached.</b>

In a polar bond, electrons are? completely transferred
<b>OK</b>

What determines the polarity of a bond? molecular shape only
<b>No. The polarity of a bond is determined by the electronegativity difference between the two elements forming the bond</b>

What determines the polarity of a molecule?electronegativity difference only
<b>No. The net polarity (net dipole moment) of a molecule is determined by two things:
a. The polarity of individual bonds, AND
b. the symmetry of the molecule.
To have a net dipole moment, a molecule MUST have both (a) individual bond polarity AND (b)the molecule must NOT be symmetrical.</b>