Question

if this 70g banana was placed in a closed container and it decomposed, what would happen to its mass? the mass would become bigger. nothing, the mass would stay the same. the mass would be smaller than it was.

Explanation:

According to the law of conservation of mass, in a closed system (the closed container), the total mass of substances before and after a chemical or physical change (decomposition in this case) remains the same. The banana decomposes, but all the mass (including mass of gases produced, etc.) is still within the closed container.

Answer:

Nothing, the mass would stay the same.