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.
Atoms are part of elements. In other words, each element is made up of atoms. Atoms are made up protons, electrons and neutrons, also called subatomic particles. Together, protons, neutrons and electrons, are called nucleons. Protons, neutrons and electrons are made up of even smaller particles, called quarks. The center of an atom is called a nucleus. The nucleus is pushed together by the strong nuclear force. The nucleus is made up of protons and neutrons. Protons are positively charged and neutrons have no charge. Around the nucleus are electrons.