Answer: 1. AgF + CaCl2 = AgCl + CaF2
2. C2H4 +O2 = CO2 +H2O
3. K2S = K+S
4. O2 + Mg = MgO
5. Mg + AlBr3 = MgBr2 + Al
6.C2H6O + O2= CO2 + H2O
7.Li2SO4 + MgCl2= Li2SO4 + MgCl2
8.HCl + Zn= H2 + ZnCl2
Explanation:
Balance the equation 
 Write down your given equation.
Write down the number of atoms per each element that you have on each side of the equation.
Always leave hydrogen and oxygen for last.
If you have more than one element left to balance:
Add a coefficient to the single carbon atom on the right of the equation to balance it with the 3 carbon atoms on the left of the equation.
Balance the hydrogen atoms next.
Balance the oxygen atoms. 
 
        
             
        
        
        
Answer:
energy from the sun that reaches earth
 
        
                    
             
        
        
        
Answer:
They are pollinators of alfalfa.
Explanation:
Without them crops wouldn't be here.