foundations in chemistry(physical) Flashcards
(60 cards)
what is the mass and the charge of proton, neutron and electron
proton: 1 , +1 electron 1/2000, -1, neutron 1, 0
what is the mass number
protons& neutrons
what is the atomic number
number of protons in the nucleus
how do you calculate number of neutrons
mass number- atomic number
what is an ion
an atom that has gained or lost an electron to gain an overall charge
what is an isotope
atoms of the same element with the same proton number but different neutron number
how are electrons significant
the number and arrangement of them dictates the chemical properties of an atom
how do isotopes differ in physical properties
they may have different densities, diffusion rates etc..
what did john dalton discover
(19th century)described atoms as solid spheres, different spheres made different elements
what did JJ thompson discover and when
1897, did experiments and found atoms werent solid and indivisible. He discovered electrons and formed the plum pudding idea
plum pudding model?
positive sphere with negative electrons embedded in it
What did Rutherford discover and when
(1909) did the gold foil experiment, fired alpha particles at a thin sheet of gold.
plum pudding model should’ve shown most of alpha particles deflected but only some did with some going through and some going straight back. Developed nuclear model
nuclear model?
tiny charged nucleus at atoms centre surrounded by a cloud of electrons and mostly empty space
what did Rutherford then go on to discover
he discovered protons as Mosely discovered the charge of the nucleus increased from one element to another.
what did James Chadwick discover
then discovered neutrons as the nucleus seemed too heavy
what were Bohr’s principles
-electrons in fixed orbits/shells
-each with a fixed energy
-when electrons move energy level electromagnetic radiation is lost of absorbed
-radiation has a fixed frequency
what else did Bohr discover
that some atoms did react due to full/stable outer shells
up to date atomic model
-never know where an electron is going
-it can act as a wave
relative atomic mass definition(Ar)
weighted mean mass of an atom compared to 1/12th the mass of a c 12 atom
relative isotopic mass definition(Ar)
mass of an isotope relative to 1/12th the mass of a c12 atom
relative molecular mass definition(Ar)
average mass of a molecule/ formula unit compared to 1/12th of an atom of of c12
relative abundance equation
relative isotopic mass*relative isotopic abundance added up/100
what is a mass spectra
devices used to find mass of samples. eg relative atomic mass
mass spectrum equation
relative isotopic mass*relative isotopic abundance added up/isotopic abundances
