Structure of the Atom Atoms consist of:Protons (+ve) Neutrons(neutral) Electrons (-ve) Protons and neutrons are in the nucleus and have similar masses(1800x that of an electron). Atoms with the same number of protons but different neutrons are called ISOTOPES. E.g.C(major isotope) 1C(~1%,used in carbon NMR) C(radioactive,used in Carbon dating) Almost all the mass of an atom is in the nucleus,but it is the electrons that are involved in the chemical bonding and reactions of an atom. Electronic Structure of the Atom Electrons display wave-particle duality. Electrons are located in orbitals around a nucleus,but the Heisenberg Uncertainty Principle tells us that we cannot pinpoint exactly where the electron is. So we use the term ELECTRON DENSITY,which is the probability of finding the electron in a particular part of the orbital. ORBITAL:is an allowed energy state for an electron,with an associated probability function that defines the distribution of electron density in space. Chol Introduction (landscape) Page 2Ch01 Introduction (landscape) Page 2 Structure of the Atom Atoms consist of: Protons (+ve) Neutrons (neutral) Electrons (-ve) Protons and neutrons are in the nucleus and have similar masses (1800x that of an electron). Atoms with the same number of protons but different neutrons are called ISOTOPES. E.g. 12C (major isotope) 13C (~1%, used in carbon NMR) 14C (radioactive, used in Carbon dating) Almost all the mass of an atom is in the nucleus, but it is the electrons that are involved in the chemical bonding and reactions of an atom. Electronic Structure of the Atom Electrons display wave-particle duality. Electrons are located in orbitals around a nucleus, but the Heisenberg Uncertainty Principle tells us that we cannot pinpoint exactly where the electron is. So we use the term ELECTRON DENSITY, which is the probability of finding the electron in a particular part of the orbital. ORBITAL: is an allowed energy state for an electron, with an associated probability function that defines the distribution of electron density in space