Psychologists of the Twentieth Century will also be Remembered

Psychologists of the Twentieth Century will also be Remembered

In addition to Pearson and Thorndike, Watson, Pavlov, Werdhimer, Kof Ka, and Kohler have also contributed to the field of education through psychological experiments.

 Vardhimer, Kohler and Kofka have contributed to the development of the Gestast theory.

 In the twentieth century, Kurtlevin has expanded new horizons in the field of psychology, with an emphasis on the study of the child's personality and Sigmund Freud's emphasis on the unconscious mind and analysis.

 The contribution of Afrid Adler and Yuga among the important educational psychologists of the twentieth century will also be remembered.

 Thus, educational psychology as an independent branch of psychology has been able to establish itself as an important subject until the development of the twentieth century.

Hence psychology is called the science of behavior.  The current definition of psychology is now generally accepted by all teachers and psychologists. 

 Thus, at the end of the study of psychology from ancient times to modern times, it can be said that psychology is the science of studying human behavior.  In support of this view we will look at the psychology terminology of some psychologists.

Educational psychology is that branch of psychology

Educational psychology is that branch of psychology

Educational Psychology: Historical Background About Educational Psychology Skinner notes that, "Educational psychology is that branch of psychology which deals with teaching and learning." - Skinner Educational psychology is a branch of psychology that touches on teaching and learning. According to Sickner, educational psychology dates back to the time of Aristotle, but Pastellozi, Habante, and Fobel have made important contributions to giving it an important autobiographical form. 

 "In the eighteenth century, Rousseau called for education through individual freedom, self-expression and activity. Pastelology (1746–1827) emphasized the development of knowledge, reasoning power through the senses. Howell (1782–1827) emphasized education through activity according to the psychological needs of children. In the nineteenth century, Darwin made important contributions to the field of educational psychology through the theory of evolution.

 This brought a unique light to the field of biological psychology. Psychologists such as Francis Gatton (1822-1911), Wilhelm Wood (1832-19: 20), and Stanley Hall have made important contributions to the development of academic psychology as a branch. Hulbert Spencer, William James, and John Dewey also made important contributions in the early twentieth century. How important in the field of evaluation and measurement in the last phase of the nineteenth century contributed to psychology.

Spectrometers have been Developed which use Deflection

 Spectrometers have been Developed which use Deflection

Mu-mesons are elementary particles having mass 207 times and charge equal to that of an electron. When a beam of mu-mesons is incident on nuclei like graphite, mu-mesons move in Bohr orbits which have got radius 207 țimes shorter and energy 207 times greater than that of an electron. When these mu-mesons are excited and de-excited, they emit mesonic X-rays.

 The obseryed experimental values of energies of X-rays dépend upon the value of nuclear radius and are usęed to estimate the size of the nucleus. The average value. of nuclear radius found by this method is equal to (1.20 ± 0.03) A x 1015 m.

 Electron Scattering Method The most important method of finding thẻ electric charge distribution inside atomic nucleus is based on the elastic scattering of électrons by nuclei as a function of scàttering angle: The charge distribution in the nucleus is obtained from the best fit to the experimental dáta óf electrons scatteréd in the enèrgy| range from 50 MeV to 1 BeV.

 It gives the following charge distribution p(r) as a function of distance, 'r, from the nuclear.centre:
and'spectrometers have been developed which use deflection of positively charged ions by the applieation of electric and maghetic fields in evacuated chambers to estimate their nueléar mass. Aston's mass spectrograph and Dempster's mass-speetrometër are two typical- instruments which aré described as follows: may.

Focussing device which focuses the particles

 Focussing device which focuses the particles 

Used to estimate the masses of nuclei and relative abundahce of various isotopes, It plays an important role for: accurately estimáting masses of nuclei and atoms, binding energy, nuelear reactions, disintegration studjes and study of other important nuclear properties. The mass spectrometers generally.consist of the following essential components.

An ion source capable of emitting beams of positively charged atomic and molecular particles which äre johized. (ii) Collimatộr slits which limit the beam to a narrow width and accelérate these, (iif) An analyzer which consists of an electric field applied perpendicular to the path of the particle and is used as an energy filter and a magnetic field applied in the perpendicular plane which is used as a momentum filter.

 (iv) Focussing device which focuses the particles of the same mass travelling with a spread of velocities in different directions along the median plane of the beam. (v) Detector consist of a photographic plate which may carry the image of ions in a masSS spectrograph or an electrode connected to a sensitive electrometer which collects pulses of current produced by a number of ions falling on it pér unit. time. A numbèr of mass spectrographs .

Density of nuclear matter cup be Estimated

  Density of nuclear matter cup be Estimated 

Various nuclei. Ahe density of nuclear matter cup be estimated from the ratio of nuclcar ss and nuclear volume and is of the order of about 2 x 10" kg/m which extremely high. The density of some of stars like white dwarfs is also very high and is cómparable to the density of nuclear matter, oment, This is also confirmed from other static and dynamic properties 1.3 Nuclear Mass The nuclear nass had been éarlier estimated in terms of atomic mass- unit which was defined as egual to 1/16th of mass of neutral O0 isótope whose mass was taken exactly equal to 16.00.

 Ho ver, International Union of Pure and Applied Physics adopted a differe, unit of mass in 1960 which was defined as thất unit of mass which is equal to 1/12th of mass. of C4 heutral isotope whose imass was taken exactly equal to 12.0000. The atomic mass.

 Unit is equal to 1.66043 x 10 27 kg. The masses of all the nuclei and atoms are now expressed in terms of this atomie mass unit. The,mass of proton and neutron on this scale is 1.007277 and 1.008665 mass units, respectively, The mass of hydrogen atom, which is equal to the sum of mass of a proton and an electron, is h007825 mass units. The equivalent energy, Moc produced due to conversion of 1 atómic mass unit, (amu), is equal to 1.66 x 10:21 x (3 x 10, i.e. 1.49 x 1010 Joules or about 931 MeV. Mass spectroscopic techniques are.