When a chemical reaction takes place it changes the composition of the reactants. The ways to tell if a reaction is occurring are,
1-Release of heat
2-Production of a gas
3-Formation of a precipitate
4-Change in color
Answer:
natural resources: materials or substances such as minerals, forests, water, and fertile land that occur in nature and can be used for economic gain.
renewable resources: a natural resource that is unlimited or that is naturally replenished rather quickly, such as sunlight or water
non renewable resources: (also called a finite resource) is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption.
C and A because the product of a matter will always be the same and just google A.
CH3-CH=CH2+Br2--->CH3-CH(Br)-CH2-Br
