On QUESTIONS 1. What is data modeling? Why is it important? 2. What is the Entity-Relationship model? 3. What is a relationship? 4. What are the differences among a unary relationship, a binary relationship, and a ternary relationship? 5. Explain and compare the cardinality of a relationship and the modality of a relationship. 6. Explain the difference between a one-to-one, a one- to-many, and a many-to-many binary relationship.. 7. What is intersection data in a many-to-many binary relationship? What does the intersection data describe? 8. Can a many-to-many binary relationship have no intersection data? Explain. 9. Can intersection data be placed in the entity box of one of the two entities in the many-to-many relationship? Explain. EXERCISES 1. Draw an entity-relationship diagram that describes the following business environment. The city of Chicago, IL, wants to maintain information about its extensive system of high schools, including its teachers and their university degrees, its students, administrators, and the subjects that it teaches. Each school has a unique name, plus an address/ felephone number, year built, and size in square Accessibility: Investigate 10. What is an associative entity? How does intersection data relate to an associative entity? " 11. Describe the three cases of unique identifiers for associative entities. 12. Describe the concept of the unary relationship. 13. Explain how a unary relationship can be described as one-to-one, one-to-many, and many-to-many if only one entity type is involved in the relationship. 14: Describe the ternary relationship concept. 15. Can a ternary relationship have intersection data? Explain. 16. What is a dependent entity? (See the description in the General Hardware example.) feet. Students have a student number, hame, home address, home telephone number, current grade land age. Regarding a student's school assignment, the school system is only interested in keeping track of which school a student currently attends. Each school has several administrators, such as the principal and assistant principals. Administrators are identified by an-employee number and also have a name, telephone number, and office number) MIN

1. What is data modeling? Why is it important? 2. What is the Bntity-Relationship model? 3. What is a relationship? 4. What are the differenoes among a unacy relationship, a binary relationship, and a ternary relationship? 5. Bxplain and compare the cardinnlity of arelationship and the modality of a relationship. 6. Explatin the differenco between a one-to-ono, a oneto-many, and a many-to-many binary relationship. 7. What is intersection dath in a many-to-many binary relationship? What does the intersection data doseribe? 8. Can a meny-to-many binary relationship have no intersection data? Explatn. 9. Can intersection data be plnood in the entity box of one of the two entities in the many-to-many relationship? Rxplain. 10. What is an associativo entity? How does intersection data relate to an associativo entity? 11. Describe the three cases of unique identifiers for associative entities. 12. Describe the concopt of the unary relationship. 13. Explain how a unnry relationship can be described as one-to-one, one-to-many, and many-to-many if only one entity type is involved in the relationship. 14:- Describe the ternary relationship concept. 15. Can a ternary relationship have intersection data? Explain. 16. What is a dependent entity? (Seo the description in the General Hardware example.) EXERCISES 1. Draw an entity-rolationship diagram that describes tho following business environment. The city of Chicago, It, wants to maintain information about its extenaive aystem of high schools, including its tenchecs and their university degrees, its studonts, administrators, and the sobjects that it teaches. Bach school has a uniquo name, jerrin address] Rea Students have a student number, pame, home Gdorns, hotio totephono number, cuncent grade, budase. Kogarding a student's school assignment, tho school system is only interestod in keeping Bach school hes several administrators, meh as the principal and assiatsutprincipals, Administntors are. identified bx-an-employee number and jiso hive a thinc, telephono numbar, und office number