Answer:
Substance at the beginning of a reaction- reactant
Substance at the end of a reaction- product
Number placed before a compound in a chemical equation- stoichiometric coefficient
Explanation:
In a reaction equation, the species written on the left hand side of the equation are called the reactants.
The reactants combine to form the species on the right hand side of the reaction equation called products. 
The stoichiometric coefficient is a number written before the formula of a compound in the reaction equation.
 
        
             
        
        
        
Transpiration is the progression of <em>water </em>inside a plant! So, the molecule representing transpiration is going to be good ol' H2O! =)
        
             
        
        
        
Ur cars exhaust tank ur freezer ur toaster ur microwave ur shower
        
                    
             
        
        
        
This
electronic transition would result in the emission of a photon with the highest
energy:
4p
– 2s
<span>This
can be the same with the emission of 4f to 2s which would emit energy in the
visible region. The energy in the visible region would emit more energy than in
the infrared region which makes this emission to have the highest energy.</span>