â George Mandler has described the origins of cognitive psychology in, Ulric Neisser is credited with formally having coined the term cognitive(2002). psychology (in terms of the current understanding of cognitive psychology) in his book Cognitive Psychology, published in 1967.
The melting point of fluorine is -219 Â°C (-363 Â°F). The boiling point of fluorine is -188 Â°C (-307 Â°F).
Hydrogen fluoride has an abnormally high boiling point for a molecule of its size(293 K or 20Â°C), and can condense under cool conditions. This is due to the fact that hydrogen fluoride can form hydrogen bonds. Because fluorine is the most electronegative of all the elements, the fluorine-hydrogen bond is highly polarized. The hydrogen atom carries a high partial positive charge (Î´+); the fluorine is fairly negatively charged (Î´-). In addition, each fluorine atom has 3 lone pairs of electrons.