In a chemical reaction, one or more substances called __________ are combined or broken down to form ___________.
products; reactants
products; compounds
reactants; products
reactants; elements

Question

In a chemical reaction, one or more substances called __________ are combined or broken down to form ___________. 
    products; reactants 
   products; compounds 
   reactants; products 
   reactants; elements

stormfire1 · Answer

reactants; products

ujjwal · Answer

what do you think happens in a chemical reaction?

anonymous · Answer

mmm the atoms and molecules generally split, swap or decompose structures

ujjwal · Answer

Atoms don't split.. Molecules (combination of atoms) may split.. And they may combine too.. atom also may combine.. 
Now my question is what do call those atoms or molecules which combine or decompose during a reaction?