Heyy guys, so i seriously am confused about something. Okay so the thermal stability of group two carbonates and nitrates increases down the group making it more difficult to decompose. I am unsure of the reason for this... It is because
A) at top of group the ions are smaller will a larger charge ( large charge density) and therefore result in a stronger force of attraction between the metal ion and the O2 minus of the carbonate ion thus the energy released when those two come together is great and very exothermic. And it states that for a chemical reaction to occur the erergy released when bonds are formed( when O2 minus amd metal ion meet ) must be greater then the energy required to break bonds. Therefore as a smaller metal ions is more exothermic when it meets a O2minus ion ,less additional energy is required for the reaction to take place at top of group but as you go down more additional energy is required as the reaction is less exothermic.
Or is the reason
B) a smaller metal ion at the top of the group with a large charge density has a greater polarising effect on the carbonate ions electrons thus making the bond weaker and easier to break and hence less engery required at top of group and more at bottom ???
I seriously need help becasue the text book pushes more for the first answer but my teacher for the other ....???? 😱😱😱