Answer:- 64015 J
Solution: There is 4250 mL of water in the calorimeter at 22.55 degree C.
density of water is 1 g per mL.
So, the mass of water =
= 4250 g
Final temperature of water after adding the hot copper bar to it is 26.15 degree C.
So,
for water = 26.15 - 22.55 = 3.60 degree C
Specific heat for water is 4.184 
The heat gained by water is calculated by using the formula:

where, q is the heat energy, m is mass and c is specific heat.
Let's plug in the values in the formula and do the calculations:

q = 64015 J
So, 64015 J of heat is gained by the water.
Answer:
C. It does not emit electromagnetic radiation.
Explanation:
Right now, Dark Matter is only a theory. Scientist proposed this to counter some of the strange phenomenon with matter in space.
Scientists know little about dark matter. Some say it's one of the driving forces of the universe. Currently, scientists have no way of measuring or identifying dark matter.
Answer:
Explanation:
We have in this question the equilibrium
X ( g ) + Y ( g ) ⇆ Z ( g )
With the equilibrium contant Kp = pZ/(pX x pY)
The moment we change the concentration of Y, we are changing effectively the partial pressure of Y since pressure and concentration are directly proportional
pV = nRT ⇒ p = nRT/V and n/V is molarity.
Therefore we can calculate the reaction quotient Q
Qp = pZ/(pX x pY) = 1/ 1 x 0.5 atm = 2
Since Qp is greater than Kp the system proceeds from right to left.
We could also arrive to the same conclusion by applying LeChatelier´s principle which states that any disturbance in the equilibrium, the system will react in such a way to counteract the change to restore the equilibrium. Therefore, by having reduced the pressure of Y the system will react favoring the reactants side increasing some of the y pressure until restoring the equilibrium Kp = 1.
Answer:
NUCLEAR ENERGY -----> MECHANICAL ENERGY -------> THERMAL ENERGY --------> ELECTRICAL ENERGY
Explanation:
In nuclear reactor, various energy transformations occur in order to generate electricity. Nuclear reactor converts the energy released from nuclear fission and the heat generated is removed from the reactor by a cooling system where steam is generated. The steam then drives a turbine which powers a generator to produce electricity.
A nuclear reactor is hence an equipment where nuclear chain reactions occur and control can be obtained. The nuclear reactor uses mostly uranium-235 and Plutonium-239. When these radioactive substances absorbs neutrons, they undergo nuclear fission causing the nucleus to split into two or more smaller compounds with the release of kinetic energy a form of mechanical energy, gamma radiations and others.The kinetic energy is then harnessed in the equipment as heat (thermal energy) which is received by a cooling system and steam is generated. The steam can then power the generator from which electricity is obtained (electrical energy).
So therefore, in a nuclear reactor, the nuclear energy is transformed to mechanical energy and then thermal energy which powers the generation of the electrical energy.