D) light is reflecting in the direction indicated by T.
If you are asking which is the most abundant, Uranium-238 is
Answer:
50 MHz
Explanation:
The relation between frequency and wavelength is shown below as:

c is the speed of light having value 
Given, Wavelength = 6 m
Thus, Frequency is:



Also,
Also, 1 Hz =
MHz
So,<u> Frequency = 50 MHz.</u>
B. carbon-13 is not an allotrope of Carbon.
Allotropes<span> are elements on the periodic table that have more than one crystalline form. </span>Isotopes<span> are atoms of the same element with the same atomic number but have a different mass number.
C-13 is an isotope of carbon, not an allotrope.</span>