Answer : 6.022• 10^23 atoms of potassium
Before the first behaviorist (Watson), Psychology was a part of philosophy.
Explanation:
As we know that relation between energy and wavelength is as follows.
E = 
This means that energy is inversely proportional to wavelength. So, more is the energy of an electromagnetic radiation less will be its wavelength.
Also, f = 
Hence, less will be the wavelength more will frequency of a radiation.
Gamma rays are the rays that have highest energy, small wavelength and highest frequency.
Thus, we can conclude that gamma rays are the electromagnetic radiation which has the highest frequency.
Answer: The average velocity is -0.965m/s
Explanation: The first step is to calculate the two velocities is both directions. A velocity is a distance per unit time.
V=d/ t
=-5.7/2.1
=-2.7m/s
For the other direction the velocity is
V=7.3/9.5
=0.77m/s
The average velocity the add the velocities and divide them by 2.
V=-2.7+0.77/2
V= 0.965m/s