hyperechoic is a mass that has a dark appearance.
Dark Matter.
Neutrinos are all but impossible to detect and it is thought that they may have mass. If they are found to have mass, they would be the epitome of dark matter.
It is not believed to be, but there is still very little known about dark matter, so maybe,
Depending on what source you use for reference, it seems somewhere between 68% and 75% of the universe is dark energy accelerating the expansion, and somewhere between 25% to 32% is matter (dark or visible) exerting gravitational force which would notionally be resisting that expansion. Note that dark energy itself has mass (per mass-energy equivalence) so one needs to be cautious if the subject in question is the overall mass of the universe or what fraction of the overall mass tends to oppose that expansion - which dark energy does not.
Easter vigil
These helped predict the existence of dark matter. Dark matter in astronomy is used appear as the result of mass, where no actual mass can be seen.
Current theory states that it's "dark energy".
Dark matter's strength is proportional to it's mass. This means that more dark matter in one spot is stronger then a little bit of dark matter in that same spot.
Yes, dark matter has a lot of mass. It makes up about 20% of the universe (much more than regular matter). Since it has mass, it also has energy. In fact, dark matter's mass is the main reason we even know it exists. Astrophysicists can observe its gravitational effects, though it is extremely hard to detect in any other way.
Any mass that possesses a proton and or neutrons within its nucleus is a chemical. Aside from dark matter, any ordinary mass is already a chemical.
oxygen