All categories

3 years ago

Black holes are the final stage of what star

2 answers:

8 0

“A black hole will suck in any nearby stuff it can. If a star or galaxy is rotating around a black hole this will be meta-stable with the gravity of the black hole matching the rotational acceleration of the star. Various events that produce imbalance, like interactions between different bodies and solar wind, allow the black hole to pick up the resulting debris.

Over time, the black hole will clear out it’s neighborhood. As the universe is expanding, and looks like it continue to do so indefinitely, our black hole will end up alone in a region of empty space.

Hawking radiation is a process at the “edge” of the black hole where quantum randomness results in creation of a particle and antiparticle pair on either side of the event horizon. One falls back into the black hole and the other radiates into space. This will slowly evaporate the black hole. This is a extremely slow process. It relies on the chance creation of particles pairs in a miroscopically thin surface bridging the event horizon. It has been calculated that this would take 10^67 years to evaporate a black hole with the mass of the Sun.

(Compare with the age of the universe, 10^10 years, and you can see how imperceptibly slow this process is. During your lifetime a black hole the mass of the Sun would lose way much than a microgram. By the time the black hole has radiated its mass, all stars will have long burned out, and the universe will have expanded so much that there are enormous and still increasing gaps between everything that even light will never cross.)

If the theory is right, and nothing unexpected happens in the long, long intervening time, the black hole will eventually evaporate in a final flash and all that will be left is an extremely weak radiation in apparent empty space”.

Andreyy893 years ago

4 0

Answer:

This:

Explanation:

Black holes occur when a massive star or larger reaches the final stage of it's lifespan. The star implodes and a black hole is the dying star's remains

You might be interested in

Reaction of hypochlorous acid and ammonia is product-favored system at equilibrium. Answer A: Reaction of hypochlorous acid and

pickupchik [31]

Answer:

A. True

B. False

Explanation:

Reaction between hypochlorous acid and ammonia does not yields a Ph value of 7.00 , this value is defined to water and no other reaction can yield exactly this Ph value. The acid reaction will give a Ph value below 7 while a base reaction will give Ph value of above 7.

7 0

3 years ago

A. Based on the activation energies and frequency factors, rank the following reactions from fastest to slowest reaction rate, a

deff fn [24]

Answer:

A) $E_{a} = 350KJ/mol$ , $E_{a} = 50KJ/mol$ , $E_{a} = 50KJ/mol$

A = 1.5× $10^{-7}s^{-1}$ , A = 1.9× $10^{-7} s^{-1}$ , A=1.5× $10^{-7} s^{-1}$

B) 4.469

Explanation:

From Arrhenius equation

$K=Ae^{\frac{E_{a} }{RT} }$

where; K = Rate of constant

A = Pre exponetial factor

$E_{a}$ = Activation Energy

R = Universal constant

T = Temperature in Kelvin

Given parameters:

$E_{a} =165KJ/mol$

$T_{1}=505K$

$T_{2}=525K$

$R=8.314JK^{-1}mol^{-1}$

taking logarithm on both sides of the equation we have;

$InK=InA-\frac{E_{a} }{RT}$

since we have the rate of two different temperature the equation can be derived as:

$In(\frac{K_{2} }{K_{1} } )=\frac{E_{a} }{R}(\frac{1}{T_{1} } -\frac{1}{T_{2} } )$

$In(\frac{K_{2} }{K_{1} } )=\frac{165000J/mol}{8.314JK^{-1}mol^{-1} }.(\frac{1}{505} -\frac{1}{525} )$

$In(\frac{K_{2} }{K_{1} } )$ = 19846.04×7.544× $10^{-5}$ = 1.497

$\frac{K_{2} }{K_{1} }$ = $e^{1.497}$ = 4.469

6 0

3 years ago

sample of atmospheric gas collected at an industrial site is stored in a 250 mL amber glass bottle that has a pressure of 1.02 a

Nady [450]

Answer:- New pressure is 0.942 atm.

Solution:- The volume of the glass bottle would remain constant here and the pressure will change with the temperature.

Pressure is directly proportional to the kelvin temperature. The equation used here is:

$P_1T_2=P_2T_1$

Where, $T_1$ and $T_2$ are initial and final temperatures, $P_1$ and $P_2$ are initial and final pressures.

$T_1$ = 20.3 + 273.15 = 293.45 K

$T_2$ = -2.0 + 273.15 = 271.15 K

$P_1$ = 1.02 atm

$T_2$ = ?

Let's plug in the values in the equation and solve it for final pressure.

$1.02atm(271.15K)=P_2(293.45K)$

$P_2=\frac{1.02atm*271.15K}{293.45K}$

$P_2$ = 0.942 atm

So, the new pressure of the jar is 0.942 atm.

5 0

4 years ago

In order for a process to be spontaneous, Multiple Choice the entropy of the surroundings must increase. the entropy of the surr

Crazy boy [7]

Answer:

The correct answer is entropy change of the surrounding plus the entropy change of the system must be positive.

Explanation:

The term entropy is a state function.Entropy can be defined as the disorder or randomness of the molecules in a system.

A spontaneous reaction is a type of reaction which deals with the release of free energy.The change of free energy in case of spontaneous reaction is always negative.

According to the second law of thermodynamics a spontaneous reaction will occur in a system if the total entropy of both system and surrounding increases during the reaction.

8 0

3 years ago

How many moles of CaCl2 are contained in 0.448 L of a 0.85 M CaCl2 solution?

kati45 [8]

Answer:

0.3808

Explanation:

number of moles,n=Conc.XVol.

hence 0.85X0.448

3 0

3 years ago