The correct Answer for this question is D
<span>U-236 spontaneously decays to Br-87, X and three neutrons. The element X is 4. La, also known as Lanthanum, number 57 in the periodic system of elements.</span>
Answer:
By measuring it's Radical velocity using Doppler Phenomenon...
Explanation:
It is done by measuring the absorption spectrum produces by a star as a result of measuring Doppler's relative wavelength. The star with the lower speed must have lower absorption spectrum extent as compared to the faster one.
I believe the correct answer from the choices listed above is the fifth option. Of the following , the strong electrolyte would be NH4NO3. NH4NO3<span> is a salt and completely dissociates in aqueous solution. Hope this answers the question. Have a nice day.</span>