Based on the activity series, which metals could x represent in the reaction below? a. sr b. al c. sn d. au

Answer: option a.explanation.the question is incomplete. you should have shown the reaction on which x appears.any way, this question intends that you use the activity knowledge about the metals to predict which can replace x.1) then, you can approach the question by analizyng the activities of the four metallic elements shown in the choices; sr, al, sn, au.2) the activity series of the metals in the list of options, plus the hydrogen is:   sr > al > sn > h₂ > au.h₂ is included as a reference.3) from that series, you have: if the element replaced has more activity than al, only sr can replace it: these are some metals more active than aluminum but less active than sr: sr > ca > na > mg > be > al.and as the first series shows, al is more active than sn and au.then if the element fo be replaced is ca, na, mg or be, only sr is more active than al,  sn and au.from which, the answer is the option a.that has to be the answer, because any other metal would lead to an ambiguos answer.