Why we used petrol for vehicles not water?

Nuclear fusion is the source of energy for stars. besides hydrogen, which other element is most likely also common in stars?

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Which statement is best described as a atom