Answer:
* 
* The solution is acidic since the pH is below 7.
Explanation:
Hello,
In this case, we can mathematically define the pH by:
![pH=-log([H_3O^+])](https://tex.z-dn.net/?f=pH%3D-log%28%5BH_3O%5E%2B%5D%29)
Thus, for the given hydronium concentration we simply compute the pH:

Thereby, we conclude the solution is acidic due to the fact that the pH is below 7 which is the neutral point and above it the solutions are basic.
Regards.
A good feeling, but i'm not sure what it's called
Answer/Explanation:
quantum of energy is important because the energy of a particle, and also how long it has had that energy, with infinite precision. Quantum, in physics, discrete natural unit, or packet, of energy, charge, angular momentum, or other physical property. the term also applicable to quanta of other forms of electromagnetic energy such as X - rays and gamma rays.
So for D you have to find energy right
from c you get wavelength Lambda
so on D use this
E = Hc / lambda
c is given 1.5 x 10 ^20
h = 6.624 x 10^-34
and then you get answer for energy