Final answer:
The statement about AB3 molecule shapes being linear, trigonal planar, or T-shaped is false; AB3 molecules are typically trigonal planar or T-shaped if there are lone pairs of electrons.
Step-by-step explanation:
The statement that possible shapes of AB3 molecules are linear, trigononal planar, and T-shaped is false. A molecule with three electron groups such as AB3 typically orients the three groups as far apart as possible, which leads to a trigonal planar geometry, as seen in molecules like BF3 where the central atom B is bonded to three F atoms. However, molecules with three bonding groups and one lone pair would present a trigonal pyramidal shape, whereas those with two lone pairs would be T-shaped. Linear configuration for AB3 is highly unlikely.
Thus, while AB3 molecules can be trigonal planar or T-shaped if there are lone pairs of electrons on the central atom, they are not typically linear unless there are particular electronic or steric constraints that force this uncommon geometry.