Answer:

Explanation:
We need to find the energy for an electron to jump from n = 1 to n = 4.
The energy in transition from 1 state to another is given by :

The difference in energy for n = 1 to n = 4 is:

So, the required energy is equal to
.
D. Mineral and fossil matches from tests done on different continents.
Answer:
B.Ionizing radiation is the correct answer.
Explanation:
Ionizing radiation has sufficient energy that it can convert atoms and molecules into ions.
It has a sufficient amount of energy that it can separate tightly confined electrons from the orbit of an atom and causing that atom to become ionized.
From the given equation we can deduce what changes will occur if the frequency of the sound is doubled
V= f (λ)
Speed = frequency. Wavelength
When the frequency is doubled, speed will not change. Because speed depends on factors like temperature, air pressure, density of the gas. Since all these factors are unchanged thus speed will remain unchanged
Frequency is the number of waves produced per second. Frequency and wavelength are inversely proportional .Thus, if the frequency is doubled the wavelength would be halved.