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35 Cards in this Set
- Front
- Back
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Cathode Rays |
Streams of negatively charged particles called electrons. They travel in straight lines from cathode to the anode and have enough energy to move a small object |
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An Energy Level |
The fixed energy value that an electron in an atom may have |
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Orbital |
A region in space within there is a high probability of finding an electron |
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Isotopes |
Atoms of the same element (same atomic number) which have different number of neutrons. |
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An Ionic Bond |
The force of attraction between oppositely charged ions in compound |
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Linear bond angle |
180° |
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Trigonal Planar |
120° |
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Tetrahedral |
109.5° |
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Pyramidal |
107° |
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V -Shaped |
104.5° |
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Electronegativity |
The relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond |
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Polar Covalent Bond |
Where there is unequal sharing of the pair (or pairs) of electrons. This causes one end to be slightly §+ and the other §- |
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Intramolecular Bonding |
Is the bonding that takes place within a molecule, it holds the atoms together. E.g Covalent/polar Covalent bonding |
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Intermolecular Forces |
Are the forces of attraction that exist between molecules e.g Van de Waals, dipole -dipole, hydrogen bonding |
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Atomic Radius |
Is half the distance between the nuclei of two atoms of the same element that are joined together by a single Covalent bond |
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First Ionisation Energy |
The minimum energy required to completely remove the most loosely bound electron from a neutral gaseous atom in the ground state |
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A Standard Solution |
Is a solution whose concentration is accurately known |
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A Primary Substance |
A substance that can be obtained in a stable,pure and soluble solid form so that it can be weighed out and dissolved in water to give a standard solution |
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Oxidation |
When an element loses electrons |
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Reduction |
When an element gains electrons |
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Oxidation Number |
Is the charge than an atom has or appears to have when electrons are distributed according to certain rules. |
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Rate of Reaction |
Is the change in concentration per unit time of any reactant or product |
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A Catalyst |
A substance that alters the rate of a chemical reaction but is not consumed itself |
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Homogeneous Catalysis |
When the reactants and the Catalyst are in the same phase. There is no boundary between the reactant and the Catalyst. |
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Heterogeneous Catalysis |
When the reactants and the Catalyst are in different phases. There is a boundary |
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Effective Collision |
A Collision that results is the formation of products |
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Activation Energy |
The minimum energy that colliding particles must have for a reaction to occcur |
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Hydrocarbon |
A compound that contains carbons and hydrogen only |
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Saturated Compound |
One with only single bonds |
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Structural Isomers |
Are compounds with the same molecular formula but different structural formula |
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Heisenberg's Uncertainty Principle |
It is impossible to measure at the same time both the velocity and the position of an electron |
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Aufbau Principle |
When building up the electron configuration in an atom in its ground state,the electron occupy the lowest available energy level. |
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Pauli Exclusion Principle |
No more than two electrons can occupy am orbital and they must had opposite spin |
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Hunds Rule |
When 2 or more orbitals odd equal energy are available, electrons occupy them singly before filling them in pairs |
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6 |
1. As long as the electron remains in its energy level it neither gains nor loses energy. 2.the energy level an electron normally occupies is the ground state. 3.when it receives a burst of energy it absorbs it and moves to a higher level (excited state) 4. It is unstable so it drop back down 5.emitting energy as a light of specific wavelength or frequently 6.the lights corresponds to particular line in the emission spectrum and is equal in energy to the difference between the two energy levels |
