What is the element of potassium permaganate

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.

Drag each label to the correct location on the chart. classify each reaction as endothermic or exothermic.

Ais a mountain created from eruptions of lava, ash, rocks, and hot gases.