For the first one it’s 69 just count the little lines from the side.
<span>The Law of Conservation of Mass simply states
that the total amount of mass should not change in a chemical reaction that is
isolated (no other objects can enter the reaction). The total mass of the
reactants must be equal to the total mass of the products. Thus, t</span>he correct estimate of
the amount of oxygen used in the interaction is the difference between 133
g and 29 g.
Scientific metod this is one of them
The proper science is validated by Experimentation and Testing .
What is experiment and testing?
Experiment is performed to support or Refuge a hypothesis which is given by someone.
Test is to figure out what we expect and what we have observed.
So , the proper validation of science is Experiment and testing because science is all about hypothesis, discoveries if want to prove them right or wrong we have to perform experiment and test .
to learn more about testing and experiment click here brainly.com/question/28175030
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