A scientist wants to use a model to help present the results of his detailed scientific investigation. Why would a model be useful?
because the model makes the concepts easier to understand
because the model is easy to put together and to use
because the model prevents other scientists from asking questions
Obecause the model requires the audience to pay full attention to it

Because the model makes the concepts easier to understand

Explanation:

Models are created to give a visual of every aspect of an experiment. This allows for a better understanding across the board for everyone.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.