Reduction takes place at the cathode and oxidation occurs at the anode.
Anode
Because of the research already gathered from scientists before him foe which he compared data with to build his own model
Answer:

Explanation:
Given that:-
Pressure = 
The expression for the conversion of pressure in Pascal to pressure in atm is shown below:
P (Pa) =
P (atm)
Given the value of pressure = 43,836 Pa
So,
=
atm
Pressure = 6.80977 atm
Volume =
= 2.3 L ( 1 m³ = 1000 L)
n = 2 mol
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the equation as:
6.80977 atm × 2.3 L = 2 mol × 0.0821 L.atm/K.mol × T
⇒T = 95.39 K
The expression for the kinetic energy is:-

k is Boltzmann's constant =
T is the temperature
So, 

I think it is trace evidence since it is really small and hard to find.