Atomic Structure And The Periodic Table Flashcards
Order of discovery of atom
John Dalton JJ Thompson Rutherford Niels Bohr Rutherford- protons James Chadwick- neutrons
Alkali metals
Group 1
Transition metals
Middle bit
Halogens
Group 7
Noble gases
Group 0
Development of the periodic table
John Newlands
Mendeleev
Mendeleev periodic table
also ordered in atomic mass but realised physical and chemical properties of elements were related to atomic mass
Switched order if properties meant it should be changed
Left gaps in table to make sure elements with similar properties stayed in the Same group.some of these gaps indicated the existence of undiscovered elements and allowed Mendeleev to predict what their properties might be
John Newlands periodic table
-Elements in order of relative atomic mass
Modern day periodic table
Arranged in order of atomic number
Elements with similar properties
In same group
Non metal properties
Dull looking Brittle Not always solid at room temp Don’t generally conduct electricity High mp and bp
Transition metals properties
Good conductors V dense Strong Shiny Ions are often coloured Make good catalysts
Group 1 elements properties
Alkali metals
Soft
Low density
Very reactive cause only one electron in outer shell
Reactivity trends of alkali metals (g1)
As you go down they-
Increase in reactivity (outer electron more easily lost cause attraction between it and nucleus is weaker as it’s further away)
Lower melting and bp
Higher relative atomic mass
Halogen properties (g7)
All non metals with coloured vapours
All exist as molecules which are pairs of atoms
F2 C2 Br2 I2
More reactive halogens displace less reactive ones
