To determine which pair of ions can form an ionic bond with each other, it's important to understand that ionic bonds occur between ions of opposite charges. These ions attract each other due to electrostatic forces.
Let's analyze each pair given:
1. [tex]$Cu^{+}$[/tex] and [tex]$Ag^{+}$[/tex]:
- Both [tex]$Cu^{+}$[/tex] and [tex]$Ag^{+}$[/tex] are positively charged ions (cations).
- Since they have like charges (both positive), they repel each other rather than attract. Thus, they cannot form an ionic bond.
2. [tex]$S^{2-}$[/tex] and [tex]$O^{2-}$[/tex]:
- Both [tex]$S^{2-}$[/tex] and [tex]$O^{2-}$[/tex] are negatively charged ions (anions).
- Similarly, since they have like charges (both negative), they also repel each other and cannot form an ionic bond.
3. [tex]$Br^{-}$[/tex] and [tex]$At^{-}$[/tex]:
- Both [tex]$Br^{-}$[/tex] and [tex]$At^{-}$[/tex] are negatively charged ions (anions).
- As both have like charges (negative), they repel each other and therefore cannot form an ionic bond.
4. [tex]$Li^{+}$[/tex] and [tex]$Br^{-}$[/tex]:
- [tex]$Li^{+}$[/tex] is a positively charged ion (cation) and [tex]$Br^{-}$[/tex] is a negatively charged ion (anion).
- They have unlike charges, which means they attract each other. This attraction due to opposite charges allows them to form a stable ionic bond.
Considering the nature of ionic bonding, the only pair that consists of ions with unlike charges, capable of forming an ionic bond, is [tex]$Li^{+}$[/tex] and [tex]$Br^{-}$[/tex]. Thus, the correct answer is:
[tex]$Li^{+}$[/tex] and [tex]$Br^{-}$[/tex]; They have unlike charges.
