What is not a guideline required for a valid evidence test?
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In the bohr model of the hydrogen atom, the energy required to excite an electron from n = 2 to n = 3 is <u>greater than</u> the energy required to excite an electron from n = 3 to n = 4
Bohr's energy levels:
The essential concept of Bohr's atomic model is that electrons occupy specified orbitals that call for the electron to have a certain amount of energy. An electron needs to be in one of the permitted orbitals and have the correct amount of energy needed for that orbit in order to be in the electron cloud of an atom. An electron would require less energy to orbit near the nucleus, while an electron would need more energy to orbit away from the nucleus. Energy levels are the potential orbits. One of Bohr's models' flaws was that he was unable to explain why just specific energy levels or orbits were permitted.
It is evident that the energy required to escape an electron from n=2 to n=3 is greater than the energy required to exit an electron from n=3 to n=4. This is because as n increases, the energy levels move closer to one another.
Learn more about Bohr's model here:
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Answer:
Explanation:
We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.
We will use the following formula to calculate heat energy.
The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.
- ΔT = final temperature - inital temperature
The aluminum block was heated from 23.0 °C to 73.5 °C.
- ΔT= 73.5 °C - 23.0 °C = 50.5 °C
Now we know all three variables and can substitute them into the formula.
- m= 225 g
- c= 0.897 J/g° C
- ΔT= 50.5 °C
Multiply the first two numbers. The units of grams cancel.
Multiply again. This time, the units of degrees Celsius cancel.
The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.
Multiply by the answer we found in Joules.
The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.
Approximately <u>10.2 kilojoules</u> of energy would be required.