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A change in which a substance changes from one physical state to another but no substances with different composition are formed. Example Gas to Liquid - Solid.

 

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Ground State

The lowest energy state or most stable state of an atom, molecule or ion.

Standard Molar Enthalphy of Formation

The amount of heat absorbed in the formation of one mole of a substance in a specified state from its elements in their standard states.

Coke

An impure form of carbon obtained by destructive distillation of coal or petroleum.

Electron Affinity

The amount of energy absorbed in the process in which an electron is added to a neutral isolated gaseous atom to form a gaseous ion with a 1- charge, has a negative value if energy is released.

Alpha (a) Particle

Helium ion with 2+ charge, an assembly of two protons and two neutrons.

Nuclear Binding Energy

Energy equivalent of the mass deficiency, energy released in the formation of an atom from the subatomic particles.

 

Salicylaldehyde

An oily, slightly water-soluble liquid, C7H6O2, having an almondlike odor: used chiefly in perfumery and in the synthesis of coumarin.

Ampere

Unit of electrical current, one ampere equals one coulomb per second.

 

Law of Conservation of Matter

There is no detectable change in the quantity of matter during an ordinary chemical reaction.

Absorption Spectrum

Spectrum associated with absorption of electromagnetic radiation by atoms (or other species) resulting from transitions from lower to higher energy states. An absorption spectrum is the inverse of an emission spectrum.