C1 - Atomic Structure & the Periodic Table

C1 - Atomic Structure & the Periodic Table

1. Structure of the atom

   • Charge
     • Electron - 1-
     • Proton - 1+
     • Neutron - 0
   • Isotopes
     • Same number of protons, different number of neutrons
       • Relative atomic mass (RAM)
         • (mass of 1st isotope x abundance) + (mass of 2nd isotope x abundance) / 100
   • Structure
     • Protons and neutrons in the tiny centre of the nucleus
     • Electrons in and around the centre
       • 2 in the 1st shell 8 in the 2nd shell 8 in the 3rd shell
       • Electrons drawn in NSEW, then double up
   • Mass
     • Electron is very small
     • Proton - 1
     • Neutron - 1

2. The Periodic table

   • Newlands
     • Arranged elements in order of atomic mass
       • Noted similar chemical reactivity in every 8th element
         • BUT mixed metals and non metals had two elements in one space
   • Group one
   • Mendeleev
     • Arranged elements in order of mass
       • Realised that some elements did not fit the pattern of reactivity
         • He left gaps for elements that had not yet been discovered

3. Separating Mixtures

   • Filtration
     • Separates and insoluble solid from a liquid
       • Equipment
         • Funnell, filter paper, conical flask
     • Residue
       • The solid left in filter paper
     • Filtrate
       • The liquid that passes through the filter paper
   • Crystalisation
     • Separates a soluble solid from a liquid
       • Equipment
         • Evaporation basin, electric heater
     • Evaporation
       • The liquid turns into a gas and leaves crystals of the solid behind
   • Chromatography
     • Separated inks & food colours
     • Stationary phase
       • Paper
     • Mobile phase
       • Solvent (water)
     • Rf value
       • Height of spot/height of solvent front
   • Distillation
     • Separates two liquids with different boiling points
     • Equipment
       • Rounded bottom flask, heat, condenser, beaker
     • Evaporation of one liquid happens in a rounded bottom flask
       • The vapour condenses in the condenser and collects in the beaker
         • The other liquid doesn't evaporate and stays in the rounded bottomed flask