A compound is labeled as CaH\(_2\). What is its molecular formula?

• A. CaH\(_2\)
• B. CaH
• C. Ca\(_2\)H\(_2\)
• D. Ca\(_2\)H

Answer: (A)

Verified step by step guidance

1. Identify the elements present in the compound notation CaH\(_2\). Here, Ca stands for calcium and H stands for hydrogen.
2. Understand that the subscript number following an element symbol indicates the number of atoms of that element in one molecule of the compound. In CaH\(_2\), the subscript 2 applies to hydrogen, meaning there are two hydrogen atoms.
3. Recognize that if there is no subscript after an element symbol, it means there is only one atom of that element. Since there is no subscript after Ca, there is one calcium atom.
4. Combine the elements and their quantities to write the molecular formula. This means the molecular formula is one calcium atom and two hydrogen atoms, written as CaH\(_2\).
5. Confirm that the molecular formula matches the original notation, which is CaH\(_2\), indicating one calcium atom bonded to two hydrogen atoms.