CHEM1006 Lecture Notes - Lecture 15: Atomic Orbital, Zwitterion, Ion
Document Summary
An atom is a basic unit of matter that consists of a dense nucleus composed of positively charged protons and neutral neutrons, which is surrounded by a cloud of negatively charged electrons. If an atom has the same number of protons and electrons, it is electronically neutral. If the total number of electrons does not equal the number of protons, the atom has a net electrical charge. Any atom or molecule with a net charge, either positive or negative, is known as an ion. An ion consisting of a single atom is a monoatomic ion; an ion consisting of two or more atoms is referred to as a polyatomic ion. The positive electric charge of a proton is equal in magnitude to the negative charge of an electron; therefore, the net electric charge of an ion is equal to its number of protons minus its number of electrons.
