Answer:
F= -1 (group 7A)
Ca= +2 (group 2)
Step-by-step explanation:
oxidation #= # electrons atom gains/loses to form chemical bond
>assigned to atoms in oxidation-reduction rxn to indicate ability to donate/ gain e-
> positive oxidation #= loss of e-, negative= gain of e-
rules:
all group 2 elements (ca) have an oxidation state of 2+
group 7A (F)= -1 charge (needs to gain 1 e- to complete octet)