The empirical formula of at least four binary ionic compounds that could be formed from the calcium, chromium, chloride and sulfide ions are CaCl₂, CrCl₄, NaCl and CaS respectively.
If any compound which is composed of two different elements, one of which is a positive ion (metal), and the other is negative ion (non-metal) is called binary ionic compounds.
Hence, CaCl₂, CrCl₄, NaCl and CaS are the four binary ionic compounds.
To know more about ionic compounds, visit the below link:
https://brainly.com/question/2687188
#SPJ4