2.1.1 atomic structure and isotopes Flashcards
what is the relative mass and relative charge of an electron
relative mass: 1/1860
relative charge: -1
what is the relative mass and relative charge of an proton
relative mass: 1
relative charge: +1
what is the relative mass and relative charge of an neutron
relative mass: 1
relative charge: 0
what is the mass number
number of protons and neutrons together
what is the atomic number
number of protons.
what is an isotope
atoms of the same element with different numbers of neutrons
what was John Daltons idea of atoms
solid spheres which were made up of each element
what was JJ Thompsons idea of atoms
plum pudding model
a positively charged sphere with electrons embedded inside
what was Rutherford’s idea of atoms
he discovered the nucleus using the alpha particle scattering experiment as some particles bounced back rather than going through the gold foil
so he made a model with a positive nucleus and an electron cloud
what was Bohr’s idea of atoms
he made 4 principles
- electrons can only exist in fixed orbitals or shells
- each shell has a fixed energy
- when electrons move between shells electromagnetic radiation is absorbed or admitted
-the radiation with have a fixed frequency
what is the definition of relative atomic mass
the weighted mean mass of an atom of an element compared to 1/12th the mass of an atom of carbon-12
what is the definition of relative isotopic mass
the mass of an atom of an isotope compared to 1/12th the mass of an atom of carbon-12
what is the definition of relative molecular mass
the average mass of an atom of a molecule or formula unit compared to 1/12th the mass of an atom of carbon-12
how do we calculate relative atomic mass from isotopic abundances
the sum of all the abundances x relative isotopic mass / 100
what does mass spectroscopy tell us
what samples are made up of and relative isotopic masses
