Answer:
B.
Explanation:
The air molecules of warm air has higher energy. It causes them to move away from each other
Answer:
The Bond energy of H-Br is +366 KJ
Explanation:
Bond energy is the energy required to break one mole of a covalent bond in a gaseous molecule. It is denoted as 'E'. The bond energy for Chlorine E(Cl-Cl) molecule is +242 KJ. This means that it takes 242 KJ of energy to break the Cl-Cl bond. It also takes the same amount of energy to form Chlorine molecule from chlorine atoms.
Bond energies can be used to calculate the enthalpy of reactions
Using the example from the question
2HBr(g) + Cl2(g) -------> 2HCl(g) + Br2(g)
Two H-Br and one Cl-Cl bonds will be broken and two H-Cl bonds with one Br-Br bonds will be formed
E(Cl-Cl) = +242 KJ
E(H-Cl) = +431 KJ
E (Br-Br) = +193 KJ
E (H-Br) = ?????
Therefore, Enthalpy (ΔH) = bond breaking - bond forming
-81.1 = [2x + 242] - [(2 x 431) + 193)]
-81.1 = [2x + 242] - [862 + 193]
-81.1 = [2x + 242] - 1055
-81.1 + 1055 = 2x + 242
973.9 = 2x + 242
973.9 - 242 = 2x
731.9 = 2x
x = 731.9 / 2
x = 365.95
x = 366 KJ
x is the bond energy for H-Br which is +366 KJ
Answer:
The experimental discoveries that led Niels Bohr to propose an improved model of the atom were the line spectrum or emission spectrum of hydrogen and the photoelectric effect.
Explanation:
There are several types of electromagnetic radiation. Going from long-wavelength, low-frequency radio waves to short-wavelength, high-frequency gamma rays. This range of frequencies and wavelengths is known as the electromagnetic spectrum. Only a small part of this spectrum can be seen with the naked eye. Thus it is called the visible region of the spectrum.
If the white light is passed through a glass prism, it is possible to see that visible region as a "rainbow" of colors. But if we use a hydrogen lamp instead of an ordinary white light lamp, a discontinuous spectrum will appear. This is a group of narrow colored lines separated by dark regions. Each line corresponds to electromagnetic radiation of a specific frequency and wavelength. This emission spectrum or line spectrum is characteristic of hydrogen and, therefore, can be used to identify it.
On the other hand, Albert Einstein used the Planck's Quantum theory to explain the photoelectric effect, which consists of a beam of electrons produced when a beam of light collides with certain surfaces. This effect could not be explained by classical physics.
Einstein said that the electromagnetic radiation is quantized; it means that light and all the other electromagnetic radiations are made of little packets of energy, known as photons.
Niels Bohr tried to combine ideas from classical physics and the quantum theory to explain the line spectrum of hydrogen atom and its structure. That was the moment when he realized that electrons could not have chaotic movement around the nucleus but with specified energy values or energy levels.
Answer:Replacing Hubble's Main Computer NASA performed a battery of mechanical, electrical, radiation and thermal tests to guarantee that the computer would survive the trip to orbit, withstand bombardment by cosmic and solar radiation and work flawlessly in the extreme temperatures of space for the rest of Hubble's life.
Explanation: