What is where an object is located?

How will the emission of an alpha particle affect the atomic number of an atom

Substance a is a nonpolar liquid and has only dispersion forces among its constituent particles. substance b is also a nonpolar liquid and has about the same magnitude of dispersion forces among its constituent particles. when substance a and b are combined, they spontaneously mix.

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?