Both reactions will not take place ordinarily.
The reactivity series is a list of metals in their order of reactivities - usually in ascending or descending order.
Following this order: Li>K> Ba > Sr> Ca > Na > Mg > Al> Mn > Zn > Cr> Fe > Cd >Co > Ni > Sn > Pb> H > Sb> Bi > Cu > Ag > Pd > Hg > Pt > Au
It means that Li is the most reactive and will displace every other metal in reactions while Au is the least reactive and will not be able to displace metals of higher reactivities.
Thus, for the reaction below:
Mn +Ca0 ---> Ca+MnO
Mn is lower in reactivity than Ca and will therefore not be able to displace ca from CaO.
Also for:
Ag+NaNO3 → AgNO3 +Na
Na is higher than Ag in reactivity and will ordinarily not be displaced by Ag in the reaction.
More on reactivity series can be found here: https://brainly.com/question/10443908
