Final answer:
To calculate the number of fluorine atoms in a sample of CH₂F₂, you need to calculate the number of moles of CH₂F₂ and then multiply by Avogadro's number. In this case, there are 1.36 × 10^23 fluorine atoms.
Step-by-step explanation:
The question is asking about the number of fluorine atoms present in a sample of CH₂F₂ with a mass of 19 g. In order to calculate the number of atoms, we need to use Avogadro's number, which states that one mole of any substance contains 6.022 × 10^23 particles. First, we need to calculate the number of moles of CH₂F₂ in the sample. The molar mass of CH₂F₂ is 84.04 g/mol, so the number of moles is 19 g / 84.04 g/mol = 0.226 moles. Since there is one fluorine atom in each CH₂F₂ molecule, the number of fluorine atoms is equal to the number of molecules times the number of atoms per molecule. Therefore, the number of fluorine atoms is 0.226 moles × (6.022 × 10^23 atoms/mol) = 1.36 × 10^23 atoms.