Imagine you have a raisin sitting in a cup of water. Over time, you notice that the raisin seems to get bigger and softer. This is because of a process called osmosis.
Osmosis is like a special kind of diffusion that happens when we have a semi-permeable barrier, like a cell membrane. A semi-permeable barrier only lets certain things pass through, like water, while keeping other things out. Think of it like a filter that only allows some things to go through.
Back to the raisin example: The raisin's skin is like that semi-permeable barrier. The water outside the raisin has smaller particles, and it wants to move through the raisin's skin to where there are larger particles inside the raisin. This is because nature likes to balance things out. So, the water molecules move through the raisin's skin to where there's more stuff inside the raisin.
As more water moves into the raisin, it starts to swell up and get plumper. This happens because the water is moving from an area where there's a lot of it (outside the raisin) to an area where there's less of it (inside the raisin). This process continues until the concentration of water inside and outside the raisin is balanced.
Imagine you're at a busy dance floor, and everyone wants to go where the music is loudest. In this case, the "music" is the concentration of water or particles. The water molecules are like the dancers, moving from the less crowded area to the more crowded area until things are balanced.
So, osmosis is when water moves through a barrier to balance the concentration of particles on both sides. It's like nature's way of making sure things are fair and even.