I put them in all the time. Just put them in for all the equations. No marks are taken off. Examiners knows that you know your stuff and sometimes, it also helps answer the question (especially with ones asking about redox) Knowing them also means that you actually know waht you are doing.
I'd disagree with the above post, only put them in if the question asks for them.
You'll lose the mark if you put the wrong state symbols, even if the rest of it is right.
I am sure you will not lose marks because you are just making a note. It is like writing down a wrong equation by the side of the page. Maybe different boards do things differently!
Is it not positive marking (or whatever it is) like it was at GCSE? You could write all the junk you want in that but if you put down something right you got a mark.
I was always told that they could mark it wrong if you put the wrong state symbols, but maybe that was just my teacher trying to stop me pointlessly putting in the state symbols
I've looked through some markschemes and it often says "ignore state symbols" - which suggests to me that there is no point thinking about them unless you need to.
To the above poster - I've done a lot of past papers and I don't remember doing any questions where there has been a mark for state symbols and it hasn't been mentioned in the question. However, if you can confirm that this is the case then this is something to look out for. Personally I'd just look at how many marks it was worth, a 1 mark question will not require state symbols, a 2 mark question could.
If you look at any past papers, whenever state symbols are NOT required, it says "ignore state symbols" or something to that effect. You wont lose a mark if they didnt ask for it and you got it wrong.