The formula is simple.
Kinetic energy = Photon energy - Binding energy
In some places, binding energy is also called work function.
So, Photon energy =
=
(Here we multiply lambda by 10^(-9) to change nm to m)
=
J
Change it to ev from Joule (J)
so, Photon energy =
J =
= 7.8 eV
Now, KE = 7.8 - 3.31 = 4.57 eV
Done !!!
<h2>Answer : 1 is gamma, 2 is alpha and 3 is beta radiations.</h2><h3>Explanation :</h3>
In the given information all the radiations were stopped by the lead block, if we assume that first radiations were gamma radiation, as they were not stopped by the cloth whereas all other radiations were stopped.
In second case, aluminum foil and wood were able to block alpha and beta radiations. Whereas, paper was used to stop the alpha particles but not the gamma and beta rays. And then a thick concrete stopped all the radiations.
This clarifies that the first radiation are gamma rays, second is alpha rays and third is beta rays.
Answer:
Explanation:
The percent yield is the ratio of the actual yield to the theoretical yield.
- The actual yield is the amount obtained from performing a chemical reaction. For this problem, it is 14.8 grams.
- The theoretical yield is the potential amount from performing a chemical reaction at maximum performance. For this problem, it is 23.5 grams.
We can substitute the known values into the formula.
Divide.
Multiply.
The original measurements for the theoretical and actual yields have 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place.
The 7 to the right, in the hundredths place, tells us to round the 9 up to a 0. Since we rounded up to 0, we have to move to the next place to the left and round the 2 up to a 3.
The percent yield is approximately <u>63.0 percent.</u>
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