CHEMISTRY Iseotops are atoms of the same element consisting the same number of protons but different number od nutrons Heiseberg principle states that we cannot give the exact place and speec of an electron in a moment of time Aufbau principle states that electrons states that electrons will always enter the lowest energy level and will continue so until that level is full Paulis principle states that no orbital may hold more than two electrons and two electrons in the same orbital will have oppsing spins Atomic orbital is the probability area of finding the electron The quantum numbers show the energy states of an electron 4 quantum numbers are Principal Orbital Magnetic Spin Chemical bond is the power that holds together the atoms in a molecule Ionic bond is the bond between metals and non metals Covalent bond is a pair of electrons shared between two atoms of non-metals