SCHEDULE CHANGE. A planned change or a flight number/time change which can occur up to more than 72 hours prior to the flight's scheduled. departure. Examples - Change of flight times, change of flight numbers, reduction of service, discontinuation of all service. in a market. American uses an automated schedule change process up to 72 hours prior to departure. Through this automated. process all schedule changes are sent to the booking source for notification.
Describe the particles that make up the nucleus of an atom in terms of mass and charge. Protons, neutrons and electrons. Protons have a relative mass of 1 and a charge of +1, they are found in the nucleus of an atom.
The Atomic Mass Number or simply the Mass Number of an atom is defined as sum of the number of the protons and the number of neutrons in the nucleus of the atom. The number of protons in the nucleus is called atomic number (Z). The total number of protons and neutrons is called mass number (A).