SQL & PL/SQL :: Find Difference Between Two Table With Respect To Column?

I have two tables tab1 and tab2 with below data Now requirement is to find difference between two table with respect to column "serial_no" which exist only in table tab1 so as per below at serial_no 2 CC4 in tab1 but CC2 in tab2 so this is different how to dump out this data

TAB1
SQL> select * from tab1;

PARENT CHILD ROW_ID SERIAL_NO
-------------------- -------------------- ---------- ----------
P1 CC1 101 1
P1 CC4 104 2
P1 CC5 105 3
P1 CC2 102 4
P1 CC3 103 5

TAB2
SQL> select * from tab2;
PARENT CHILD PREVIOUS_ROWID ROW_ID NEXT_ROWID
-------------------- -------------------- -------------- ---------- ----------
P1 CC1 0 101 102
P1 CC2 101 102 103
P1 CC3 102 103 104
P1 CC4 103 104 105
P1 CC5 104 105 0

create table tab1(parent varchar2(20), child varchar2(20),row_id integer,serial_no integer);

insert into tab1 values('P1','CC1',101,1);
insert into tab1 values('P1','CC4',104,2);
insert into tab1 values('P1','CC5',105,3);
insert into tab1 values('P1','CC2',102,4);
insert into tab1 values('P1','CC3',103,5);

create table tab2(parent varchar2(20), child varchar2(20),previous_rowid integer,row_id integer,next_rowid integer);

insert into tab2 values('P1','CC1',0,101,102);
insert into tab2 values('P1','CC2',101,102,103);
insert into tab2 values('P1','CC3',102,103,104);
insert into tab2 values('P1','CC4',103,104,105);
insert into tab2 values('P1','CC5',104,105,0);