Amedeo Avogadro (1776-1856). Gives the relationship between volume and amount when pressure and temperature are held constant. Remember amount is measured in moles. Also, since volume is one of the variables, that means the container holding the gas is flexible in some way and can expand or contract.medeo Avogadro (1776-1856). Gives the relationship between volume and amount when pressure and temperature are held constant. Remember amount is measured in moles. Also, since volume is one of the variables, that means the container holding the gas is flexible in some way and can expand or contract.
Definition of presidence. plural. -s. 1 : the action or fact of presiding : direction, superintendence by the presidence and guidance of an unseen governing power â William Wollaston. 2 : presidency 1a preserve both the senate and the presidence â P. G. Hamerton.
Valence Definition. Valence is typically, the number of electrons needed to fill the outermost shell of an atom. Because exceptions exist, the more general definition of valence is the number of electrons with which a given atom generally bonds or number of bonds an atom forms. (Think iron, which may have a valence of 2 or a valence of 3.) The IUPAC formal definition of valence is the maximum number of univalent atoms that may combine with an atom. Usually, the definition is based on the maximum number of either hydrogen atom or chlorine atoms. Note the IUPAC only defines a single valence value (the maximum), while atoms are known to be capable of displaying more than one valence. For example, copper commonly carries a valence of 1 or 2.