Why do matter densities increase?

Matter densities increase when stuff gets squished together more tightly.

Imagine you have a big box full of marbles, that’s like matter. Now, if you shake the box really hard and then put a lid on it, the marbles get pushed closer together. That means there are more marbles in the same space, which makes the density higher. It's like when you pack your toys into a smaller backpack before going to school, everything gets tighter.

When matter is heated up or squeezed, the particles that make it move less and get closer together. Think about a balloon filled with air, when you press on it, the air inside gets more crowded, just like marbles in our box.

If you cool down something, like ice cream, the molecules slow down and stay close, making it even denser than liquid milk or cream.

So, whether it's your backpack getting full, a balloon being pressed, or ice cream becoming solid, density increases when things get more crowded.