I wrote argon too, we'll definitely lose all the marks. If you write the wrong thing the mark scheme says CE = 0 meaning you can't get any marks if you write the wron answer even if your explanation is justifiable
For the question on the highest melting point, I was contemplating Aluminium (as it was 3+) and Silicon, but I put Aluminium, which is wrong. I gave a good, full explanation but any ideas if they will put CE=0 or if they have in the past for a similar question, or will they credit the explanation part?