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Attractive interactions between polar molecules, that is, between molecules with permanent dipoles.

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Heterogeneous Equilibria

Equilibria involving species in more than one phase.

Activation Energy

Amount of energy that must be absorbed by reactants in their ground states to reach the transition state so that a reaction can occur. In other words, activation energy is the minimum energy required for a chemical reaction to occur.

Atomic Weight

Weighted average of the masses of the constituent isotopes of an element, The relative masses of atoms of different elements.

Phosphorus Oxychloride

Colorless to slightly yellow fuming liquid.

Mol. Wt.: 153.39
M.P.: 20C
B.P.: 105.1C
Density: 1.685 @ 15.5C
Vapor Pressure: 40 mm @ 27.3C
Vapor Density: 5.3
Used as the phosphorus source for phosphorus diffusion.

Electromotive Series

The relative order of tendencies for elements and their simple ions to act as oxidizing or reducing agents, also called the activity series.


A two-armed barometer.

Nitric Acid

HNO3: A strong acid, it is toxic and can cause severe burns. Transparent colorless or yellowish, fuming, suffocating, caustic and corrosive liquid. Nitric acid boiling point is 83C. A 70 percent solution is used in the S.S.E. laboratory for junction depth measurements. Nitric acid is also present in the metal etch solution used for the Aluminum etch procedure.


The direct solidification of a vapor by cooling, the reverse of sublimation.

Differential Thermometer

A thermometer used for accurate measurement of very small changes in temperature.

Standard Reaction

A reaction in which the numbers of moles of reactants shown in the balanced equation, all in their standard states, are completely converted to the numbers of moles of products shown in the balanced equation, also sall at their standard state.