The empirical formula represents the simplest whole-number ratio of atoms in a compound. To find the empirical formula of C10H4, we need to find the greatest common factor (GCD) of 10 and 4, which is 2.

Dividing both subscripts by 2, we get:

C10H4 -> C5H2

Therefore, the empirical formula of C10H4 is C5H2.