chemistry aqa a level topic 1 with correct answers

JJ Thomson Plum pudding model sphere of positive charge with negative charges distributed evenly Rutherford -electron shell model -gold foil experiment with alpha particles -small dense central nucleus surrounded by orbiting electrons 00:18 01:36 nucleus -nearly the entire mass -protons and neutrons make it positive -in a neutral atom the number of protons=electrons number of electrons in shell 2n^2 where n is the number of shell -each shell must fill before holding another electron Relative isotopic mass The mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12. Relative atomic mass The weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12. mass number the sum of the number of neutrons and protons in an atomic nucleus represented in an equation using A relative atomic mass takes the.... relative abundances of isotopes into account relative abundance mr= mean mass of atom/1/12xmean mass of c-12 isotope isotopes Atoms of the same element that have different numbers of neutrons neutral atoms of isotopes will... react chemically in the same way as their proton number and electron configuration is the same however different mass number of isotopes... will mean different physical properties ions positively and negatively charged atoms Vaporization The sample is vaporized Ionization The vapor is ionized by a bombardment with high energy electrons and their knocked out their atoms Acceleration The positive ions are accelerated by an electric field so that they all have the same kinetic energy