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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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Metal

An element below and to the left of the stepwise division (metalloids) in the upper right corner of the periodic table, about 80% of the known elements are metals.

Combination Reaction

Reaction in which two substances (elements or compounds) combine to form one compound.

Ternary Acid

A ternary compound containing H, O, and another element, often a nonmetal.

Emission Spectrum

Spectrum associated with emission of electromagnetic radiation by atoms (or other species) resulting from electronic transitions from higher to lower energy states.

 

Joule

A unit of energy in the SI system. One joule is 1 kg. m2/s2 which is also 0.2390 calorie.

Radical

An atom or group of atoms that contains one or more unpaired electrons (usually very reactive species)

Heterogeneous Equilibria

Equilibria involving species in more than one phase.

Ion Product for Water

Equilibrium constant for the ionization of water, Kw = [H3O+][OH-] =1.00 x 10-14 at 25 °C.

Quantum Numbers

Numbers that describe the energies of electrons in atoms, derived from quantum mechanical treatment.

Shielding Effect

Electrons in filled sets of s , p orbitals between the nucleus and outer shell electrons shield the outer shell electrons somewhat from the effect of protons in the nucleus, also called screening effect.