It makes it easier to see in dark places
Answer:
as it travel through the space it behave like a wave and has an oscillating electric field components and an oscillating magnetic field
Answer:
Halving the wavelength doubles the frequency and, thus, doubles the energy of the incident photons. This doubles the energy given to each electron, nearly doubling its kinetic energy after it is free from the metal.
Answer:
A procedure according to the norms.
Explanation:
If possible, proceed to fix the leak in no more than 30 days from the moment it was discovered.
Otherwise, during the first 30 days develop a planification to backfit the leak or, if needed, retire the appliance. This should be executed within one year.
Answer: 
Explanation:
The mean free path 
of an atom is given by the following formula:
(1)
Where:
is the Universal gas constant
is the absolute standard temperature
is the diameter of the helium atom
is the Avogadro's number
absolute standard pressure
Knowing this, let's find from (1), in order to find the radius 
of the helium atom:
(2)
(3)
(4)
If the radius is half the diameter:
(5)
Then:
(6)
(7)
However, we were asked to find this radius in nanometers. Knowing 
:
(8)
Finally:
This is the radius of the helium atom in nanometers.
