Answer:
what is the question please?
Answer A material that decreases the rate of a reaction. The amount of energy that reactants must absorb before a chemical reaction will start also called free energy of activation. What role does activation energy pay in chemical reactions? Activation energy is the energy absorbed before it can start a chemical reaction.
Explanation:
Answer:


Explanation:
h = Planck's constant = 
c = Speed of light = 
m = Mass of electron = 
= Work function = 
= Velocity of A particle = 
= Velocity of B particle = 
The wavelength is given by


The wavelength 

The wavelength 
Answer: 
Explanation:
Given
Distance between two speakers is 8 m
Man is standing 12 away from the wall
When the person moves 3 parallel to the wall
the parallel distances from the speaker become 4+3, 4-3
Now, the difference of distances from the speaker is

Condition for destructive interference is

for second destructive interference; n=2

They rely on human, and our reaction times can vary.