Answer:
E) The rate of the reaction is directly proportional to the concentration of the reactant.
Explanation:
Give the characteristic of a first order reaction having only one reactant.
A) The rate of the reaction is not proportional to the concentration of the reactant.
B) The rate of the reaction is proportional to the square of the concentration of the reactant.
C) The rate of the reaction is proportional to the square root of the concentration of the reactant.
D) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant.
E) The rate of the reaction is directly proportional to the concentration of the reactant.
 
        
             
        
        
        
Answer:
I think it both physical & chemical change :')
 
        
             
        
        
        
Answer:
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Explanation:
There will be a transfer of thermal energy (heat) from the hot metal plate to the surrounding air. This transfer of energy equates to a transfer of kinetic energy in the molecules. As the plate loses heat, the molecules in the plate will lose kinetic energy and slow down. As the surrounding air gains heat, the molecules will gain kinetic energy and speed up.
 
        
             
        
        
        
This is the balanced eq
N2 + 3H2 -> 2NH3
first you need to find mole of N2 by using
mol = mass ÷ molar mass.
mol N2= 20g ÷ (14.01×2)g/mol
 =0.7138mol
then look at the coefficient between H2 and NH3. 
it is N2:NH3 
 1:2
 0.7138:0.7138×2
 0.7138:1.4276 moles
moles of NH3 = 1.4276 moles
        
             
        
        
        
C, The atomic mass. This could also cause certain elements (i.e. Uranium, Plutonium) to radioactively decay in process called nuclear fission.