Question

1. choose the best answer. what is the cause of the various molecular shapes? the electrostatic attraction of valence electrons the electrostatic attraction of atomic nuclei the electrostatic repulsion of valence electrons the electrostatic repulsion of atomic nuclei 5) choose the best answer. what accounts for the differences between the trigonal planar and trigonal pyramidal molecular shapes? a double bond on the central atom a triple bond on the central atom lone pair of electrons on the central atom different number of bonded pairs on the central atom

Explanation:

For question 4: Molecular shapes are determined by the repulsion between negatively charged valence electrons, as these repulsions dictate how electron domains arrange themselves around a central atom to minimize energy.
For question 5: A trigonal planar molecule has no lone pairs on the central atom (3 bonding pairs only), while a trigonal pyramidal molecule has one lone pair on the central atom (3 bonding pairs + 1 lone pair); this lone pair creates extra repulsion that distorts the shape from planar to pyramidal.

Answer:

1. the electrostatic repulsion of valence electrons
2. lone pair of electrons on the central atom