4.75 billion years ago, a large star near what is now the Solar System went supernova, sending heavy element debris outward into the galaxy. Some of the debris, after traveling long distances through space, collided with a Hydrogen cloud.
Answer:
An increase of 3,500 J
Explanation:
Given that,
Energy added by swimmer = 12000 J
Heat removed by the surrounding = 8500 J
We need to find the total change in energy. It can be calculated using the law of conservation of energy such as :

As the change in energy is positive, it means that there is an increase of 3500 J.
it would be (D) because you cant see an atom without a microscope and a model is a larger model of the actual thing.
Gene (DNA) expression would be B