Which substances are not ionized in a aqueous solution?

Question

Hi, KBr, H2SO4, HON2, AgCl, Ca(NO3)2

Answer 1

I haven't heard of HON2. All of the others are ionized although I wonder if you have misused the term; i.e., AgCl is very slightly soluble but it iws ionized none the less. H2SO4 is 100% ionized for the first H but only slightly for the second.