Dark energy and dark matter seem over analyzed, although they are no different than gravity and wind. Dark energy can be the pulling caused by black holes, stars, and large planets. Dark matter also is just the effect of cosmic dust and debris pushed from explosions but also pulling caused by distant gravitational bodies.
IDensity is calculated by mass divided by volume. As you half the Hershey bar, mass and volume change by the same proportion. Therefore, density is the same.
Answer:
wave speed slow down as it hits different material
Answer: “Formaldehyde” is emitted from most manufactured building materials and furniture.
