Prediction tutorials

  PERIODIC TABLE :   “ The periodic table is a tabular method of displaying the elements in such a way, that the elements having similar properties occur in the same vertical column or group”. Earlier attempts of the classification of elements: Dobereiner’s Triads, Newland’s law of octaves. Dobereiner’s Triads:   This classification is based on the atomic mass. According to this, when elements are arranged in order of increasing atomic masses, groups of three elements, having similar properties are obtained. The atomic mass of middle element of the triad being nearly equal to the average of the atomic masses of the other two elements. For Example Li (6.9), Na (23), K (39). Limitation: It fails to arrange all the known elements in the form of triads, even having similar properties. Newland’s Law of Octaves:   According to this ‘when elements are placed in order of increasing atomic masses, the physical and chemical properties of every 8th element are a repetition of the properties of th

  Electricity:   Electric current, electric circuit, voltage or electric potential, resistance and (Ohm’s law). Electric Current:   The flow of electric charge is known as Electric Current, Electric current is carried by moving electrons through a conductor. By convention, electric current flows in the opposite direction to the movement of electrons.                                                                    Electric Circuit:   Electric circuit is a continuous and closed path of electric current.                        Expression of Electric Current:   Electric current is denoted by the letter ‘I’. Electric current is expressed by the rate of flow of electric charges. Rate of flow means, the amount of charge flowing through a particular area in unit time. If a net electric charge (Q) flows through a cross-section of a conductor in time t, then, Where I is electric current, Q is a net charge and t is a time in second.                                              S.I. Unit of Ele