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.
Atomic mass number. The nucleus is made up of protons and neutrons, the number of protons defines which element it is and gives the nucleus its positive charge. The neutrons create different isotopes. The sum of the protons and neutrons is the number of nucleons in the nucleus, this is called its mass number.If you have 6.02x10^23 atoms, it will weigh its atomic weigh in grams. This number is called Avagadro's constant. eg.he neutrons create different isotopes. The sum of the protons and neutrons is the number of nucleons in the nucleus, this is called its mass number. If you have 6.02x10^23 atoms, it will weigh its atomic weigh in grams.