Final answer:
The bond between cesium and iodine is ionic, as is the bond between lithium and chlorine, because in each pair, a metal bonds with a nonmetal, resulting in the transfer of electrons and the formation of oppositely charged ions.
Step-by-step explanation:
The bond between cesium and iodine is ionic, because cesium is a metal and iodine is a nonmetal. Metals tend to lose electrons and form positive ions, while nonmetals tend to gain electrons and form negative ions. When cesium (Cs) loses an electron to iodine (I), it forms the positively charged cesium ion (Cs+), and iodine gains an electron to form the negatively charged iodide ion (I-). The electrostatic attraction between these oppositely charged ions results in an ionic bond, forming cesium iodide (CsI).
Similarly, lithium is a metal and chlorine is a nonmetal, which means the bond between them is also ionic. Lithium (Li) can lose an electron to form a lithium ion (Li+), while chlorine (Cl) can gain an electron to form a chloride ion (Cl-). The compound formed by these ions, lithium chloride (LiCl), is held together by the ionic bond due to the attraction between the positively charged lithium ion and the negatively charged chloride ion.