1. Explain why a table with a primary key consisting of only one column that is on the 1st normalform is automatically on the 2nd normal form?2. What is the requirement for a table to be on the 3rd normal form?3. In ER modelling, what kind of table relationships (Cardinalities) exist?4. In ER modelling, what is a unique identifier and what does it become when a model is converted to a database?