To answer this question, we need to understand the physical and chemical properties of calcium iodide (CaI2), carbon disulfide (CS2), and sodium fluoride (NaF).
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Calcium Iodide (CaI2):
- It is an ionic compound formed from the calcium cation (Ca²⁺) and iodide anions (I⁻).
- CaI2 typically has high melting and boiling points, is solid at room temperature, and is soluble in water.
- It conducts electricity when dissolved in water due to the presence of ions.
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Sodium Fluoride (NaF):
- It is also an ionic compound formed from the sodium cation (Na⁺) and fluoride anions (F⁻).
- NaF shares similar properties with CaI2, including being solid at room temperature, having high melting and boiling points, and being soluble in water. It also conducts electricity when dissolved.
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Carbon Disulfide (CS2):
- CS2 is a molecular compound consisting of carbon and sulfur atoms.
- It is a liquid at room temperature with a lower melting point and boiling point compared to CaI2 and NaF.
- CS2 is nonpolar, does not conduct electricity, and is not ionic. It is also largely insoluble in water but soluble in organic solvents.
Given these comparisons:
- CaI2 and NaF are both ionic compounds and have similar physical properties.
- Both of these compounds (CaI2 and NaF) differ significantly from CS2, which is a molecular compound with very different properties.
Based on this analysis, the correct option is:
A. CaI2 has properties that are more similar to NaF than CS2.