Can a element be lost or gained in a chemical reaction

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

Which statement best describes the function of enzymes?

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2