ATOMS IONS AND COMPOUNDS Flashcards
What is Mr ( Molecular mass )
Number of protons + Number of neutrons
What is Atomic Number
Number of protons / electrons
What is an Ion
An atom of an element with a different number of protons and electrons
What is an isotope
an atom of an element with a different number of neutrons
Atom theory 1803
John Dalton said atoms were spheres and each element was a different sphere
Atom theory 1897
JJ Thompson discovered the electron and came up with the plum pudding model which was a cloud of protons with electrons embedded within
Atom theory 1909
Ernest Rutherford suggested there was a very small nucleus which was positively charged and that the atom was mainly empty space
What was the gold leaf experiment
Positive alpha particles were fired at gold leaf and some deflected back suggesting that they hit a positively charged nucleus
1913 atom theory
Niels Bohr proposed that electrons were in fixed energy shells
Relative atomic mass
Mean mass of an atom of an element compared to 1/12 the mass of a carbon-12 atom
Relative isotopic mass
mass of an atom of an isotope compared to 1/12 mass of a carbon-12 atom
what is m/z
mass divided by charge, usually the same as the isotopic mass
How to calculate atomic mass on a mass spectra
(Abundance of A x m/z) + (Abundance of B x m/z) divided by total abundance of sample
how are ions created
electrons transfer from one atom to another
List formulae for these ions
Hydroxide
nitrate
ammonium
sulphate
carbonate
zinc
silver
OH-
NO3-
NH4+
SO42-
CO32-
Zn2+
Ag+
