Respuesta :

Answer:

  • Law of conservation of mass
  • Naming "Oxygen"

Explanation:

1.Law of conservation of mass : Matter can neither be created nor destroyed in a chemical reaction .

or

Total mass of Reactants should be equal to total mass of product.

Use : This law is used to balance the chemical reaction

it helps in calculating amount of product formed

2.Naming "Oxygen":

He deduced  that combustion and respiration  are occuring from some molecule. He named that element as "Oxygen"