In diffusion, the net movement of a substance travels down its concentration gradient Explain using the image below.

Diffusion is the movement of molecules from the higher concentration to lower concentration.

Diffusion is the movement of molecules from the area of higher concentration to the area of lower concentration. In the image, higher concentration of molecules are present on the left side whereas lower number of molecules are present on the right side of the image.

So here diffusion occurs by movement of molecules from higher concentration to lower concentration means from left to right side of the image until the concentration becomes equal so we can conclude diffusion is the movement of molecules from the higher concentration to lower concentration.

Learn more: link

The diagram is a representation of the diffusion.

Explanation:

In this image, there are molecules or concentrations of a particular substance is represented by the purple circle on both sides of the box in left side concentration is higher than the right side.

So the movement of these molecules is from the left corner to the right down the concentration gradient, this type of movement of the substance is known as the diffusion which moves from high concentration to low concentration.

"d.) carbon dioxide and hydrogen sulfide"