If you want to put the CamelCase names to your database objects, your create object script should have been with in double quotes like below:
create table "temp_2"
(“col1” number constraint "temp_2_pk" primary key, col2 number);
select * from "temp_2"
select * from user_tables where table_name ='temp_2'
Without double-quotes Oracle helpfully converts all identifiers to uppercase.