physical features of modern periodic table

Rutherford's Atom Model (Main Features) - (i) Every atom consists of a nucleus containing the entire +ve charge. The whole mass of atom is concentrated at this core. (ii) The size of the nucleus i.e., 10 - 1 5 m is very small compared to the size of the atom (i.e., 10 - 1 0 m). (iii) The ..

A radioactive nucleus or element emits an alpha or a beta particle and gets converted into a new nucleus or element. The process of destruction of the original nucleus during the formation of new nucleus due to radioactivity is called Radioactive decay or disintegration. When a α - particl..

Simple Pendulum Time Period of Oscillation Varies with Time - Let us now find out how Time Period of oscillation vary with time. Set up a simple pendulum and measure the time taken for 10 oscillations of the simple pendulum for different lengths like 10,20,40,60,80 and 100 cm. T..

> Point of intersection of medians of the triangle Rectanqular or cubical block Point of intersection of diagonals Consider a ceiling fan in your room. When it is on, each point of its body goes in a circle. If we locate the centres of the circles traced by different particles on the three blades o..

The number of protons or the number of electrons in an atom in its normal state is called the atomic number and is denoted by Z. The nucleus of every element contains Z protons and some number of neutrons. The electrons, having the same charge as a proton but of opposite sign, nullify the charge of..

Moseley had done experiments on the characteristic X-rays and this led to the development of the concept of atomic number. The periodic table was made according to the atomic weight in earlier days. But some anomalies were found in such an arrangement. Moseley measured the frequ..

Let a tuning fork be fixed vertically near the rim of a circular turntable. On sounding the fork and spinning the turn table, a periodic variation in the pitch of the sound will be observed. It increases when the fork is moving towards the observer and decreases when it is mov..

Weather Satellites - Scientists who investigate weather phenomenon are called meteorologists. To study a particular feature, may require an observation from a larger area. By combining great number of observations and analysing them by computers it is possible to get information about a l..

The age of fossils of plant or animal origin can be determined by carbon dating technique developed by Willard Libby in 1949. The radioactive isotope of carbon ( 6 C 1 4 ) is used to determine the date at which an animal or plant had died. Carbon Dating The method of measuring the age of arch..

>Unit of Mass is defined as "the mass of a particular solid cylinder made of platinum-iridium alloy kept in Paris, known as the International Prototype Kilogram". Unit of time, second, is equal to the duration of 9192631770 periods of the radiation corresponding to the transition between ..