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Atomic Structure And The Periodic Table - Coggle Diagram
Atomic Structure And The Periodic Table
Simple Model Of The Atom, Symbols, Relative Atomic Mass, Electronic Charge And Isotopes
Mixtures
Easily separated
Chromatography
Filtration
Crystallisation
Distillation
Simple
Fractional
Contain at least two different elements or compounds
No chemical bonds
Chemical properties of components unchanged
Atoms, Elements And Compounds
Atoms
Smallest part of an element that can exist
Radius of 0.1 nanometres
Isotopes
Same number of protons, different number of neutrons
Relative atomic mass
Calculated using masses and abundances of each isotope
Elements
Made up of atoms with the same atomic number
Compounds
Contain two or more elements
Formed by chemical reactions
Electronic Structure
Configurations of the first 20 elements
E.g. Nitrogen: 2,5
Electrons occupy lowest energy levels
Inner shells filled first
Diagrams
Maximum electrons for first 3 shells: 2,8,8
Subatomic Particles
Electrons
Negatively charged
Protons
Same number of protons and electrons in an atom
No overall charge
Positively charged
Atomic number
Mass number- sum of protons and neutrons
Neutrons
Neutral charge
Relative masses
Protons: 1
Neutrons: 1
Electrons: 1/2000
Atomic Model Development
New evidence leads to new models
Discovered electrons
Initially believed atoms were tiny undividable spheres
Plum pudding model
Nuclear model
Bohr model
Bohr suggested electrons orbit in shells
Tiny positive nucleus at the centre
Alpha scattering experiment
Ball of positive charge with electrons scattered in it
Discovered electrons
Later experiments
Discovered protons and neutrons
James Chadwick
The Periodic Table
Structure
Period
Row
Each period represents new shell of electrons
Position used to predict reactivity
E.g. Group 1 reacts more violently down the group
Group
Column
Group number equals number of outer shell electrons
Elements in the same group have similar chemical properties
In order of atomic number
Metals And Non-Metals
Metals
High melting points
Form positive ions
Strong, malleable, good conductors
Towards bottom left of periodic table
Non-Metals
Do not form positive ions
Brittle, dull looking, don't conduct electricity
Towards top right of periodic table
Development
Initially periodic tables were ordered by atomic weight
Early tables were incomplete
Some elements placed in incorrect groups
Mendeleev
Left gaps
Undiscovered elements
Didn't follow strict atomic mass
Ensured elements with similar properties lined up in groups
Isotopes discovered after Mendeleev
Same chemical properties
Different atomic masses
Groups
Group 0
Noble gases
Unreactive
Full outer shell
Stable
Boiling point increases down the group
Group 7
Halogens
Displacement
More reactive halogens displace less reactive halogens
Molecules of two atoms, e.g. Cl2
Down the group...
Melting and boiling points increase
Reactivity increases
Harder to gain an electron
Group 1
Alkali metals
One electron in outer shell
Very reactive
Form ionic compounds
Reactions with...
Water
Chlorine
Oxygen
Properties Of Transition Metals
Typical properties
Good catalysts
Iron catalyst in Haber process
Nickel catalyst for the hydrogenation of alkenes
Speeds up the rate of reaction without being used up
General properties of metals still hold
Dense, shiny and strong
Good conductors of electricity
Colourful compounds
E.g. Fe2+ ions are green
Form more than one ion
E.g. Copper forms Cu+ and Cu2+ ions
Comparison to group 1 elements
Group 1 metals do not form coloured compounds
Much less reactive than Group 1 metals
Demonstrated by relative reactions with water, oxygen and halogens
Group 1 metals do not form more than one ion
Stronger, harder and denser
Higher melting points