As for these 2, the first one probably could get 2 marks if you included just a bit more yapping/info. The second one however you fail to acknowledge HOW the experiment influenced the atomic model. Merely jumping straight to what aspect Chadwick changed fails to account for what about his...
Marks don't matter in school its ranking. Keep the ranking as consistently high as possible and you'll be in control of your own marks (most of the time)
If it helps you, I did not do very well for my first 2 assessments in geography but aced my trials by a considerable margin over 2nd which allowed me to jump from ~4th to 1st. Which then let me get my own assessment mark since I was the only one who got a b6.