By definition, the universe is everything in ... We measure the geometry of the universe by measuring the average density of matter in space and comparing it to a critical density, which dictates ...

Solids also have a high density, meaning that the particles are tightly packed together. In a liquid, the particles are more loosely packed than in a solid and are able to flow around each other ...

While you convince them that your answer is correct, here is a picture of my ... the volume of the water displaced (V d) and using the density of water (ρ w) along with the gravitational field ...

So for heaviness, we can go with the mass definition or we can talk about ... of the atoms in question but at a different quantity: density. Density is the mass per unit of volume.