One last thing.
I varied this sentence since we are going to involve students from different third classes.I don't know how to express the second part.
Pupils taken from different (or various) tenth classes will be involved in the project since the scientific project's topics are dealt with in the scientific subjects of the class curriculum, namely of natural sciences (biology, chemistry, earth science) and physics
Pupils taken from different tenth classes will be involved in the project since the project's topics are included in the scientific subjects of this class curriculum, namely the natural sciences (biology, chemistry, earth science) and physics.
(I'm not clear on the difference between "tenth classes" and "third classes." Can you explain?)