The answer would be the Scientific Method.
Answer:
D) diffraction
Explanation:
Corona is an optical phenomenon produced by the diffraction of sunlight or moonlight, as light moves through water droplets in the atmosphere.
This phenomenon produces one or more diffuse concentric rings of light around the Sun or Moon, usually seen as colored circles.
Therefore, the explanation for these phenomena of colored concentric circles, sometimes seen with the Sun or the Moon involves diffraction.
Answer:
Explanation:
We can use the work function equation for a photoelectric experiment:

- h is the plank constant
- c is the speed of light
- λ is the wave length
- K is the kinetic energy (or K=eΔV)
So we will have:
I hope it helps you!
Answer:
The uncertainty in the position of the electron is 
Explanation:
The Heisenberg uncertainty principle is defined as:
≥
(1)
Where
is the uncertainty in momentum,
is the uncertainty in position and h is the Planck's constant.
The momentum is defined as:
(2)
Therefore, equation 2 can be replaced in equation 1
≥
Since, the mass of the electron is constant, v will be the one with an associated uncertainty.
≥
(3)
Then,
can be isolated from equation 3
≥
(4)
But 
Hence, the uncertainty in the position of the electron is 