W was the 19th letter and was pronounced "wah"; there was an equivalent letter in the old Baybayin script of the Philippines. In the International Phonetic Alphabet, is used for the voiced labial-velar approximant. W is the symbol for the chemical element tungsten, after its German (and alternative English) name, "Wolfram". It is also the SI symbol for the watt, the standard unit of power. Double-u, whose name reflects stages in the letter's evolution when it was considered two of the same letter, a double U, is the only modern English letter whose name has more than one syllable. It is
Melting point the same space. The Lindemann criterion states that melting is expected when the vibration root mean square amplitude exceeds a threshold value. Assuming that all atoms in a crystal vibrate with the same frequency "ν", the average thermal energy can be estimated using the equipartition theorem as where "m" is the atomic mass, "ν" is the frequency, "u" is the average vibration amplitude, "k" is the Boltzmann constant, and "T" is the absolute temperature. If the threshold value of "u" is "ca" where "c" is the Lindemann constant and "a" is the atomic spacing, then the melting point is estimated