What isotope has mass of 204 and 124 neutrons?

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

Some molecular compounds, such as hcl, ionize completely in solution. for molecular compounds such as h2co3, most molecules do not ionize in solution. which describes the properties of these two solutes? a. hcl and h2co3 have the same effect on the properties of the solution. b. hcl raises the freezing point of water more than h2co3 does. c. hcl raises the boiling point of water more than h2co3 does.

What volume does 1.70 ×10–3 mol of chlorine gas occupy if its temperature is 20.2 °c and its pressure is 795 mm hg?