Year 12 predicted a level grades

Hi, I'm a year 12 who just did my mock exams and have started getting my results back. I got a b in maths and physics when I need an a* in both and am unsure on what to do to get predicted the a* I need. In maths, I have been consistently getting 72% or more in all my assignments but in physics, at the start of the year I was getting Cs and Ds but since february, I have been getting only As. I really want to get a predicted an a* but don't know what to do to prove to them that I can

It's up to your school / college to decide what evidence they need to produce an accurate prediction. So you'll need to ask them what evidence they need to see.