The Council shall determine its own rules and keep a journal of its proceedings and may punish or expel any Member for conduct unbecoming of an elected official or violation of its rules and declare his/her seat vacant for absence without valid excuse where such absence has continued for two months. No expulsion shall take place without the concurrence of two-thirds of all the Members elected and until the delinquent Member has been notified of the charge against him/her and has had an opportunity to be heard.