Equation for the reaction btn nitric acid and metal X whose valence is 3​

(a) Reaction of nitric acid with non-metal:
C+4HNO
3
​
⟶CO
2
​
+2H
2
​
O+4NO
2
​

S+6HNO
3
​
⟶H
2
​
SO
4
​
+2H
2
​
O+6NO
2
​

(b) Nitric acid showing acidic character:
K
2
​
O+2HNO
3
​
⟶2KNO
3
​
+H
2
​
O
ZnO+2HNO
3
​
⟶Zn(NO
3
​
)
2
​
+H
2
​
O
(c) Nitric acid acting as oxidizing agent
P
4
​
+20HNO
3
​
⟶4H
3
​
PO
4
​
+4H
2
​
O+20NO
2
​

3Zn+8HNO
3
​
⟶3Zn(NO
3
​
)
2
​
+4H
2
​
O+2NO

hope that helps you please mark brainliest

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.