Final answer:
The symbols for the ions and the correct formula for the ionic compounds are: A. Ca²⁺ and Cl⁻, CaCl₂; B. Rb⁺ and Br⁻, RbBr; C. Li⁺ and N³⁻, Li₃N; D. Ca²⁺ and S²⁻, CaS.
Step-by-step explanation:
When two elements combine to form an ionic compound, one element loses electrons to become a positive ion (cation), while the other element gains electrons to become a negative ion (anion).
A. Calcium loses two electrons to become Ca²⁺ while chlorine gains one electron to become Cl⁻. Therefore, the symbols for the ions are Ca²⁺ and Cl⁻, and the formula for the ionic compound formed is CaCl₂.
B. Rubidium loses one electron to become Rb⁺ while bromine gains one electron to become Br⁻. Therefore, the symbols for the ions are Rb⁺ and Br⁻, and the formula for the ionic compound formed is RbBr.
C. Lithium loses one electron to become Li⁺ while nitrogen gains three electrons to become N³⁻. Therefore, the symbols for the ions are Li⁺ and N³⁻, and the formula for the ionic compound formed is Li₃N.
D. Calcium loses two electrons to become Ca²⁺ while sulfur gains two electrons to become S²⁻. Therefore, the symbols for the ions are Ca²⁺ and S²⁻, and the formula for the ionic compound formed is CaS.