What is the difference between elements and compounds?

Why are the trends and exceptions to the trends in ionization energy observed?

The conventional equilibrium constant expression (kc) for the system below is: 2icl(s) ⇄ i2(s) + cl2(g) [cl2] ([i2] + [cl2])/2[icl] [i2][cl2]/[icl]2 none of the listed answers are correct [i2][cl2]/2[icl]

The identities of substances are the same before and after which type of change