I thinking the limitation is that a shifting electron will always move from a more excited states to a less excited state. Electrons could not circle the nucleus because they would lose energy by emitting electromagnetic radiation and spiral into the nucleus. In addition Bohr was not able to explain electrons orbits of large atom w/many electrons.
Answer:
Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density. Hot water is less dense and will float on room-temperature water. <u>Cold water is more dense and will sink in room-temperature water.</u>
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Sliding or rolling friction
Answer: so the answer is A
Explanation: The relationship between an object's mass (m), its acceleration (a), and the applied force (f) is F=ma. ... This law requires that the direction of the acceleration vector is in the same direction as the force vectors.
Answer: Option (b) is the correct answer.
Explanation:
Kinetic energy is defined as the energy obtained by the molecules of an object due to their motion.
Also, it is known that kinetic energy is directly proportional to temperature.
Mathematically, K.E = 
where, T = temperature
Whereas potential energy is defined as the energy obtained by an object due to its position.
Mathematically, P.E = mgh
where, m = mass
g = acceleration due to gravity
h = height
Therefore, in the given curve when temperature remains constant then kinetic energy of molecules will also remain.
Hence, we can conclude that the segment QR represents an increase in the potential energy, but no change in the kinetic energy.