Answer:
The correct option is (a).
Explanation:
Given that,
The energy of photon, E = 2.52 eV
We need to find the wavelength of the photon in nm. The formula for the energy of a photon is given by :

The nearest option is a) i.e. 492.34127 nm.
Answer:
15 g
Explanation:
Given,
Plutonium-244 = 30 g
We have to find the gram of Plutonium-244 left after 1 half-life.
We know that the half-life of a radioactive isotope is constant. The half-life of a Radioactive isotope does not depend on the initial amount of isotope.
Now,
After 1 half-life
Plutonium-244 left = 
= 15 g
Hence, 15 g of the Plutonium-244 will be left after 1 half-life.
There is not enough information to answer the question
The answer is A the ability to coin money:)