NEED HELP FOR 12 HS

hello everybody, so i came here to ask that , is paper checking in seba really tough I attempted 60 marks in both my physics and chemistry but i am really scared of the marking scheme due to which I can’t focus on my rest exam i would say i have attempted 35 marks fully correct i am worried about the remaining 25 because I didn’t wrote the accurate answers like just wrote the reaction instead of product and all please tell me can i score 80% if i somehow manage 80+ in all remaining subjects?