Question

how many atoms of calcium (ca) are in the compound? calcium peroxide cao₂ 1 atom 2 atoms 3 atoms

Explanation:

Step1: Analyze the chemical formula

The chemical formula of calcium peroxide is \(CaO_{2}\). In a chemical formula, the sub - script number after an element symbol represents the number of atoms of that element in one molecule of the compound.

Step2: Determine the number of calcium atoms

For the element \(Ca\) (calcium) in \(CaO_{2}\), since there is no sub - script number after \(Ca\), by the rule of chemical formula notation, it is assumed to be \(1\). While for oxygen (\(O\)), the sub - script number is \(2\), meaning there are 2 oxygen atoms. But the question asks for the number of calcium atoms.

Answer:

A. 1 atom