What substance leaves a mark on paper after crushing a sunflower seed? How can this be proved?

1. This is fat. He leaves a mark on paper.
2. Since the stain of fat does not dry out, and the water dries, you can drip a drop of water next to the grease stain. After a while, it will dry.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.