Topic 1: Atomic structure and the Periodic Table Flashcards
the atomic number (Z) of a element is
the number of protons in the nucleus of an atom of that element
the mass number of an atom is
the sum of the number of protons and the number of neutrons in the nucleus of that atom
isotopes are
atoms of the same element with different masses
the relative atomic mass (Ar) of an element is
the weighted mean (average) mass of an atom of an element compared to 1/12 of the mass of an atom of carbon-12
relative isotopic mass is
the mass of an individual atom of a particular isotope relative to 1-12 of the mass of an atom of carbon-12
the molecular ion peak is
the peak with the greatest m/z ratio in the mass spectrum, the M peak
a quantum shell defines
the energy level of an electron
an orbital is
a region within an atom that can hold up to two electrons with opposite spins
the electronic configuration of an atom shows
the number of electrons in each sublevel in each energy level of the atom
Hund’s rule states that
electrons will occupy the orbitals singly before pairing takes place
the Pauli Exclusion Principle states that
two electrons cannot occupy the same orbital unless they have opposite spins. electron spin is usually shown by the use of an upward and downward arrows
the first ionisation energy of an element is
the energy required to remove one electron from each atom in one mole of atoms in the gaseous state
the second ionisation energy of an element is
the energy required to remove one electron from each singly charged positive ion in one mole of positive ions in the gaseous state
Groups are
the vertical columns int he Periodic Table
Periods are
the horizontal rows in the Periodic Table
