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 protons and neutrons, which are called nucleons when they are talked about as the components of an atomic nucleus, add up to make the atomic mass of an atom. Strictly speaking, the electrons are included, but they weigh next to nothing, being about 1/1836th the mass of a proton.aking the world better, one answer at a time. The sum of the number of protons and neutrons in the atomic nucleus is called the mass number. For example, Lithium has 3 protons and 4 neutrons in its nucleus. It's mass number is 7 (3+4).