The region a represents the distance of the electron from the nucleus.
According to the wave mechanical model of the atom, the probability of finding an electron within a given volume element (representing the atom) is the square of the wave function psi.
Since a is the region in space where there is the greatest probability of finding the electron in the atom, it follows that distance of the electron form the atom is always a.
Learn more about the wave mechanical model: brainly.com/question/1382157
De broglie wavelength,
, where h is the Planck's constant, m is the mass and v is the velocity.

Mass of hydrogen atom, 
v = 440 m/s
Substituting
Wavelength 

So the de broglie wavelength (in picometers) of a hydrogen atom traveling at 440 m/s is 902 pm
Answer:
4°C
Explanation:
Water is densest at 4°C. Since dense water sinks, the bottom of the lake will be 4°C.
Answer:
360,000
Explanation:
This is because the density is per kilogram so you would just multiply 2400 by 150 to give you 360000.

Answer:
The velocity of the block is 231650.8 ft/s
Explanation:
Knowing
W = 10 lb
v0 = u = 4 ft/s
F = 8
lb
ms = 0.2
Applying the newton second law
ΣFy = 0
N - W = 0 --> N = W = 10 lb
ΣFx = m
F - ms N = ma
- 0.2(10) = 
a = 
Using Kinematics
a = dv/dt
=
= 
v - 4 = 3.22 
when t = 30
v = 231650.8 ft/s