What is bedrock layer

Can someone me with 3 and 4 plz. this is for masteries test.

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?

If you try to move a piano and are unable to move it, did you perform any work in the scientific sense of the word? yes no correct anwser get brainliest