Why doesnt science offer conclusive proof of phenomena

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.