Final answer:
The bond order of a molecule or ion with 10 valence electrons is likely to be 2, considering common diatomic molecules like oxygen (O2) that have this electron count and a double bond between atoms.
Step-by-step explanation:
To determine the bond order in a molecule or ion with 10 valence electrons, we can use the concept of Lewis structures. Bond order is defined as the number of bonding pairs of electrons between two atoms. For example, a single bond has a bond order of 1, a double bond has a bond order of 2, and a triple bond has a bond order of 3. Without specifying the exact molecule or ion, we can't determine the bond order solely based on the number of valence electrons. However, we can say that the bond order will not equal the total number of valence electrons, so options a (10), c (1), and d (5) are incorrect since a molecule with 10 valence electrons won't likely have a bond order of 10 or 5 and typically isn't a single bonded molecule. The correct bond order most likely corresponds to a certain arrangement of those electrons in bonds, such as in a molecule like O2 which has a bond order of 2 (option b).