Can someone please explain how to answer this?

Theoretically, which metal should be the most reactive? hydrogen lithium francium fluorine

Asap! will give brainiest when a heat wave strikes a region causing more people to run air-conditioning units, electrical demand increases. what needs to be done to meet this increased demand? raising the control rodslowering the control rodsremoving the control rods

Stage in which a typical star has completely stopped fusion