does it have multiple choice
If your findings disproves your hypothesis then your hypothesis is probably wrong.
Your answer is 1-3-2-4 , grass sand water rock
Answer: The child isotope has an atomic mass of 206.
Explanation:
Alpha decay : When a larger nuclei decays into smaller nuclei by releasing alpha particle. In this process, the mass number and atomic number is reduced by 4 and 2 units respectively.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :


THE MOLAR MASS OF FLUORINE IS 35G/MOL