Unit 1 - Chemical Changes & Structures Flashcards
A very unstable arrangement of atoms formed at the maximum of the potential energy barrier, during a chemical reaction.
Activated Complex
The minimum kinetic energy required by colliding particles before a reaction will occur, since high energy activated complex must be formed.
Activation energy
Substance which increases the rate of reaction without being used up, often a transmission metal.
Catalyst
The term used to describe the mechanism by which atoms are held together.
Chemical Bonding
Describes the way in which atoms, ions or molecules, are arranged.
Chemical structure
Of reactions suggests that, for a chemical reaction to occur, particles must collide.
Collision theory
Formed when two atoms share electrons in their outer shell to complete the filing of that shell
Covalent bond
Half the distance between the nuclei of two bonded atoms of an element.
Covalent radius
Electrons, in metallic bonding, are free from attachment to any one metal ion and are shared amongst the entire structure.
Delocalised electrons.
Molecules with only two atoms (e.g. oxygen, O2, and carbon dioxide, CO)
Diatomic molecules
An atom or molecule in which a concentration of positive charges is separated from a concentration of negative charge.
Dipole
A measure of the attraction that an atom involved in a bond has for the electrons of the bond.
Electronegativity
The energy required to remove one mole of electrons from one mole of atoms in the gaseous state.
First ionisation energy
Molecules of pure carbon constructed from 5- ad 6- membered rings combined into hollow structures. The most stable contains 60 carbon atoms in a shape resembling a football.
Fullerene
Electrostatic forces of attraction between molecules containing a hydrogen atom bonded to an atom of a strongly electronegative element such as flourine, oxygen or nitrogen, and a highly electronegative atom on a neighbouring molecule.
Hydrogen Bonding
They attract molecules together. They are weaker than chemical bonds.
Intermolecular forces
Forces of attraction which exist within a molecule.
Intramolecular forces
A regular 3D arrangement of particles in space. The term is applied to metal ions in a solid and to positive and negative ions in an ionic solid.
Lattice
The forces of attraction which result from the electrostatic attraction between temporary dipoles and induced dipoles caused by movement of electrons in atoms and molecules.
London Dispersion Forces
Fluids which mix with or dissolve in each other in all proportions
Miscible
The regular recurrence of similar properties when the elements are arranged in order of increasing atomic number.
Periodicity
A covalent bond between atoms of different electronegativity which results in an uneven distribution of electrons and a partial charge along the bond
Polar bond
Shows the enthalpy of reactants and products and the enthalpy change during a chemical reaction
Thermal chemical equation
Of a substance are their physical and chemical characteristics. These are often a reflection of the chemical Bonding and structure of the material.
Properties
The resistance to flow that is exhibited by all liquids.
Viscosity
