Storyline Part 2

Democritus- 1st to say atoms existed

John Dalton- hypothesized atoms were made of differing masses

J.J Thompson- discovered the electron

Ernest Rutherford- describes the nucleus as dense (most mass) and that the e- belongs outside the nucleus

Neil Bohr- modernized the atom by placing e- in orbitals (paths) around the nucleus

Lewis structure- tells the number of valence e-/ represented by a dot

Radioactive decay- reaction only affecting the nucleus of an atom

Alpha- when 2 protons and 2 neutrons bond together are emitted from the nucleus

Beta- too many neutrons converts into protons and electrons

Gamma- occurs when gamma rays are emitted and occurs immediately following other decays

Half life- time required for half the atoms of a radioactive nuclide to decay

Isotopes- atoms of an element with a different #n

mol- Si unit for the amount of substance

molar mass- the mass of one mole of a pure substance

Ions- another name for atoms once bonding occurs

Cations +- lose electrons

Anions- gain electrons

Parent nuclide- heaviest of the series