Given the following relational database schema:

Employee=(ID, name, position, officeN, phoneN,age)// assume the name is unique.

Committee =( title, meetingDate, startTime, endTime, location)// You may use <,>,=,!= between dates and times.

Membership= ( ID, title, task) // task = member or chair.

Use a minimum number of operations and tables to express the following queries by SQL statements:

1. List the name of every employee who is a chair of at least two committees.

2. List the name of every employee who is not serving on any committee.