Answer:
Reactants: hydrogen and oxygen
Products: water
Explanation:
The reactants are what goes into a reaction, i.e. what is reacting. The products are what is formed. The reactants are usually shown on the left, and the products are usually shown on the right.
We can see in this equation that hydrogen (2H2) is reacting with oxygen (O2) to form water (2H2O). Therefore the reactants are hydrogen and oxygen, and the product is water. 
 
        
             
        
        
        
The total energy from an isolated system is constant; energy can be changed from one form to another, but can't be created or destroyed.
        
             
        
        
        
Answer: DNA provides a set of chemical instructions to specific genes that the gene uses to make proteins in order to determine traits. 
Explanation: Genes provide instructions that are used to determine the sequence of amino acids needed to make up a protein. 
 
        
             
        
        
        
Answer:
30meter per second
Explanation:
Given that
Distance = 3000 meters
Time = 100seconds
Speed = distance /time
Substituting the values
Speed = 3000/100
Speed = 30meter per second
The average speed needed to cover the travelling will be 30meter per second.