When placed in a 100 ml cube-shaped box, a substance fills the cube and has a volume of 100 ml. when placed in a 50 ml tube, that same amount of substance fills the tube and thus has a 50 ml volume. what is the state of the substance?

The substance is a gas.

The substance takes both the shape and the volume of the container, so it must be a gas.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.