<h3>
Answer:</h3>
4.56 × 10^-19 Joules
<h3>
Explanation:</h3>
We are given;
- Wavelength of the wave as 435.8 nm
We are required to calculate the amount of energy released by an electron.
- We know that the speed of the wave, c is 2.998 × 10^8 m/s
- But, c = f × λ , where f is the frequency and λ is the wavelength
- Energy of a wave is given by the formula;
E = hf , where h is the plank's constant, 6.626 × 10^-34 J-s
But, f = c/λ
Therefore;
f = (2.998 × 10^8 m/s) ÷ (4.358 × 10^-7 m)
= 6.879 × 10^14 Hz
Thus;
Energy = 6.626 × 10^-34 J-s ×6.879 × 10^14 Hz
= 4.558 × 10^-19 Joules
= 4.56 × 10^-19 Joules
Therefore, the energy that must be released by the electron is 4.56 × 10^-19 Joules
Answer:
Three half lives corresponds to (12)3 . So a 18 quantity of the original isotope is retained. And the percentage of quantity of a radioactive material that remains after 5 half-lives will be . ∴NN0×100=10032=3.125.
The answer is 137 grams boyyy
