Louis pasteur conducted an experiment to answer the question of whether or not living things can arise spontaneously from nonliving materials. in this experiment he used two flasks of sterile broth. how could this demonstrate the invalidity of spontaneous generation?

Pasteur's flask prevented microorganisms from entering into the broth, thus the broth could not 'generate' living things as was previously believed.

Explanation:

To disprove the theory of spontaneous generation, Pasteur set up an experiment with swan neck flasks. He added broth into a swan neck flask and boiled it to sterilize the broth, then kept it for an extended period. He predicted that if the swan-neck of the flask remained intact, the broth would not be contaminated. Although air could still flow between the flask and the environment, the air-borne microoganisms were trapped in the swan neck.

When the experiment was conducted with a flask with no swan neck, the broth quickly became contaminated.

At the time, there was a popular theory that microorganisms ‘spontaneously’ arose from non-living materials. Pasteur’s experiment helped proved that they generated from parent cells.

your answer is going to be physical weathering