Is a black hole 100% black? Surrounding every black hole is an event horizon: the boundary between where an object could escape from the black hole’s gravitational pull and where everything irrevocably falls towards the central singularity. But despite that no objects from inside the event horizon escapes, black holes aren’t actually black.
Are black holes just mass?
The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of no escape is called the event horizon.
Physical properties.
Class 
Approx. mass 
Approx. radius 
Micro black hole 
up to M_{Moon}

up to 0.1 mm 
Where is black holes mass? The only place where its mass can be located is where there is no space, i.e., at the singularity. Hence, for a Schwarzschild black hole, the mass is located at the origin in spherical coordinates, the centre of its circular event horizon.
Do black holes grow in size? The universe’s black holes are bigger than astrophysicists expected them to be. Now, a new study suggests why: Every single black hole may be growing as the universe expands.
Is a black hole 100% black? – Additional Questions
Do black holes have infinite mass?
Why? Well, even though black holes are extreme in many ways, they don’t have infinite mass—and it’s mass that determines the force of their gravity. Some black holes—known as stellar black holes. —have about the amount of mass that very massive stars do.
Can black holes destroy matter?
Specifically, as we understand it now, if you fall into a black hole you are guaranteed to hit the center, which is called the singularity. At the singularity you would be crushed into a ball of almost infinite density, which would destroy anything, even atoms, protons, or quarks.
Are black holes hot?
Black holes are freezing cold on the inside, but incredibly hot just outside. The internal temperature of a black hole with the mass of our Sun is around onemillionth of a degree above absolute zero.
What is beyond a black hole?
They’re only visible when they’re feeding on stars or gas clouds that stray too close to their boundary, called the event horizon. Beyond the event horizon lies a truly minuscule point called a singularity, where gravity is so intense that it infinitely curves spacetime itself.
Can something have infinite mass?
The energy of a particle diverges to infinity as it approaches the speed of light. Since we can never have infinite energy for a particle, the speed of light cannot be reached. Since an object has infinite kinetic energy when it approaches the speed of light, it therefore has infinite mass as well.
Are black holes finite?
Black holes have a finite lifetime due to the emission of Hawking radiation. However, for most known astrophysical black holes, the time it would take to completely evaporate and disappear is far longer than the current age of the universe.
Do black holes have infinite energy?
No, the energy of a black hole is not infinite. It depends on its mass, angular momentum and charge. Infinite density at a point does not translate to infinite energy in the E=mc2 sense.
Is there a finite amount of mass in the universe?
All possible Universes are finite since there is only a finite age and, therefore, a limiting horizon. The geometry may be flat or open, and therefore infinite in possible size (it continues to grow forever), but the amount of mass and time in our Universe is finite.
Is anything truly infinite?
This means that there is always a limit on the largest value that can be scientifically measured. So the conclusion is: science (that is, physics) cannot establish existence of infinite quantities. There is nothing physically infinite.
What is the largest void in the universe?
Radio astronomers have found the biggest hole ever seen in the universe. The void, which is nearly a billion light years across, is empty of both normal matter and dark matter.
Is the time infinite?
As a universe, a vast collection of animate and inanimate objects, time is infinite. Even if there was a beginning, and there might be a big bang end, it won’t really be an end. The energy left behind will become something else; the end will be a beginning.