Final answer:
Lithium is normally found only combined with other atoms due to its high reactivity.
Step-by-step explanation:
The element that is normally found only combined with other atoms due to its high reactivity is lithium (a). Lithium is an alkali metal in Group 1 of the periodic table. Alkali metals are highly reactive and readily combine with other elements to form compounds. For example, lithium combines with fluorine to form lithium fluoride.