Answer: The number of fluorine atoms that combine with one uranium atom are 6.
Step-by-step explanation:
We are given an unknown gas of uranium and fluorine atom and when it is decomposed, it produces 2.09 parts of uranium atoms for every 1 part of fluorine atom.
Relative mass of Uranium = 238 g
Relative mass of Fluorine = 19 g
Number of atoms of uranium present in a given relative mass =

Number of atoms of fluorine present in given relative mass =

For 0.0087 atoms of uranium are produced when 0.05 atoms of fluorine are produced.
So, 1 atom of uranium are produced when =
atoms of Fluorine atoms.
Hence, 6 atoms of fluorine atoms are produced when 1 uranium atom is produced.