The answer would be C. because if you burn coal can you get the same piece of coal back?
Answer:
(2) The lowest energy orbits are those closest to the nucleus.
Explanation:
In the Bohr theory the electrons describe circular orbits around the nucleus of the atom without radiating energy, therefore to maintain the circular orbit, the force that the electron experiences, that is, the coulombian force due to the presence of the nucleus, must be equal to the centripetal force.
The electron only emits or absorbs energy in the jumps from one allowed orbit to another, with only one jump occurring at a time, from layer K (n = 1) to layer L (n = 2), without going through intermediate orbits. In said change it emits or absorbs a photon whose energy is the difference in energy between both levels.
In Bohr's model, it is stipulated that the energy of the electron is greater the greater the radius r, so the lowest energy orbits are those closest to the nucleus.
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
CF₂Cl₂ is a refrigerant. When it is evaporated, it absorbs heat from water, which cools.
<h3>What is evaporation?</h3>
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.
- Step 1: Calculate the heat released by water.
We will use the following expression.
Qw = c × m × ΔT = (4.184 J/g.°C) × 156 g × (20.5 °C - 42.9 °C)
Qw = -14.6 kJ
where,
- Qw is the heat released by water.
- c is the specific heat of water.
- m is the mass of water.
- ΔT is the change in the temperature of water.
If water releases 14.6 kJ of heat, CF₂Cl₂ absorbs 14.6 kJ of heat (Qr = 14.6 kJ).
- Step 2: Calculate the mass of the refrigerant required.
We will use the following expression.
Qr = ΔH°evap × m
m = Qr/ΔH°evap = 14.6 kJ / (0.144 kJ/g) = 101 g
where,
- Qr is the heat absorbed by the refrigerant.
- ΔH°evap is the heat of vaporization of the refrigerant.
- m is the mass of the refrigerant.
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
Learn more about evaporation here: brainly.com/question/25310095
Answer:
130
Explanation:
This is because I just took the test and it said this was the answer
