Prelim revision (Unit 1,2 and 3A) Flashcards
What is the definition of activation energy?
The energy required by colliding molecules to form an activated complex
What is the definition of the bonding continuum?
A concept applied to bonding. Ionic and covalent bonding lie at opposite ends of the bonding continuum with polar covalent bonding in between.
What is the definition of collision geometry?
A term used to describe the way reactants collide with each other
What is the definition of collision theory?
A theory used to explain the factors which lead to a successful reaction. It explains how altering variables can affect the speed of reaction.
What does collision theory require reactants to do?
Collide, have the correct collision geometry and have a minimum energy (the activation energy) before a reaction occurs.
What is the definition of covalent atomic radius?
A measure of atomic size, being half the distance between the nuclei of two covalently-bonded atoms of an element. Covalent bond lengths between any two atoms can be obtained by adding the appropriate covalent atomic radii.
What is the definition of covalent bonding?
Bond formed between two atoms by the sharing of a pair of electrons. Usually occurs with non metal atoms
What is the definition of a covalent network?
A very strong and stable structure formed by certain elements and certain compounds. All the atoms are held together by strong covalent bonds.
What are characteristics of covalent networks?
Covalent network compounds are all solids at room temperature and have very high melting points.
What is the definition of delocalised electrons?
Electrons which are not confined to a single orbital between a pair of atoms. Delocalised electrons are free to move away from the atom they came from.
What is the definition of an electron?
A particle that moves around the nucleus of an atom. It had a single negative charge but it’s mass is negligible compared with that of a proton or neutron.
What is the definition of electronegativity?
The strength of attraction by an atom of an element for its bonding electrons.
What is the definition of an endothermic reaction?
A reaction in which heat energy is absorbed from the surroundings. It has a positive enthalpy change
What is the definition it an exothermic reaction?
A reaction in which heat energy is released to the surroundings. It has a negative enthalpy change
What is the definition of group?
A column of elements in the Periodic Table
What is the definition of intermolecular bonds?
Bonds between molecules.They are much weaker than intramolecular bonds
What is the definition of intramolecular bonds?
Bonds within molecules
What is the definition of a covalent bond?
Bond formed as a result of attraction between positive and negative ions
What is the definition of ionisation?
The loss or gain of electrons by neutral atoms to form ions
What is the definition of ions?
Atoms or groups of atoms that possess a positive or negative charge due to loss or gain of electrons
What is the definition of a lattice?
The 3D arrangement of positive and negative ions in the solid, crystalline state of ionic compounds.
What is the definition of London dispersion forces?
The weak forces of attractions between all atoms and molecules, caused by temporary dipoles
What is the definition of metallic bonding?
The bonding responsible for typical metallic properties. Each atom loses its outer electrons to form positive ions
How are ions packed in metallic bonding?
The ions pack together in a regular crystalline arrangement with the electrons delocalised through the structure, binding the ions together
Name 3 examples of metallic properties?
Malleability, ductility and electrical conductivity in metals and alloys
What is the definition of monatomic?
A term used to describe the noble gases since they are composed of individual atoms which do not bond to each other. They are held together by London dispersion forces in the liquid and solid state
What is the definition of a non-polar covalent bond?
A covalent bond where both atoms share the electrons weakly
Where does non-polar covalent bonding occur?
Between all elements that exist as molecules, since the atoms joining are identical. It also occurs in compounds where the bonding atoms have a small difference in electronegativity
What is the definition of nucleus?
The extremely small centre of an atom
What is found in the nucleus of an atom?
Neutrons and protons
What is the definition of permanent dipole-permanent dipole interactions?
The attraction between molecules which possess a permanent dipole because of the presence of polar bonds
What is the definition of polar covalent bonds?
Bonds formed between non-metallic atoms by sharing a pair of electrons. If the atoms have considerably different electronegativities, the electrons are not shared equally, the more electronegative atoms becoming slightly negative in comparison with the other atom. As a result it is non-polar
What is the definition of an activated complex?
An unstable arrangement of atoms formed at the maximum of the potential energy barrier during a reaction
What is the definition of alkanals?
A homologous series of aldehydes
What is the general formula for alkanals?
C (n) H(2n) O
What is the definition of alkanes?
A homologous series of saturated hydrocarbons eg methane
What is the general formula for alkanes?
C (n) H (2n + 2)
What is the definition of alkanoic acids?
A homologous series of carboxylic acids
What is the general formula for alkanoic acids?
C (n) H (2n) O (2)
What is the definition of alkanols?
A homologous series of alcohols
What is the general formula for alkanols?
C (n) H (2n + 1) OH
What is the definition of alkanones?
A homologous series of ketones
What is the general formula for alkanones?
C (n) H (2n) O eg. propanone
What is the definition of alkanes?
A homologous series of unsaturated hydrocarbons. Each member contains a carbon-carbon double bond
What is the definition of an alkyl group?
A group of carbon and hydrogen atoms forming a branch in a carbon compound
What is the definition of an amide link?
Group of atoms formed by the condensation polymerisation of amino acids in the formation of protein chains. The amide link is -CO-NH- and occurs between each pair of amino acid residues in the chain.
What is the definition of amino acids?
Compounds of general formula, H2NCHRCOOH, which link by condensation reaction to form proteins.
What is the definition of an antioxidant?
Compounds that slow oxidation reactions
What is the definition of a carbonyl group?
The functional group present in ketones, C=O
What is the definition of a carboxyl group?
The functional group present in carboxylic acids, -COOH.
Where does name for a carboxylic group derive from?
The name derives from the fact that the carboxyl group contain a carbonyl and hydroxyl group