The diagram shows the potential energy changes for a reaction pathway. part 1: describe how you can determine the total change in enthalpy and activation energy from the diagram, and if each is positive or negative.
part 2: describe how the curve will look if the reaction was exothwrmic. be sure to mention changes in the potential energies of the reactants and products and the sign changes of the enthalpy.​

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

im not exactly sure but i think its b!

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.