the nuclear age summary

Summary - Radioactivity Spontaneous emission of active rays by certain unstable elements. Three types of radiations are: (i) Alpha particles He 2 + ion (Helium nuclei). (ii) Beta - rays - consist of electrons. (iii) Gamma - rays - High energy electromagnetic rays. Emission of alpha partic..

Summary - Today most of our energy needs are supplied by the fossil fuels. In one hundred years coal will be the only one left as petroleum products may remain only for 3 to 4 decades. Little of stored energy will be left if we continue to use energy at the same rate. Fossil fuels are non..

Growth is an irreversible increase in size and weight of an organism. The cells of the body do not grow uniformly but differentially. The main types of growth are auxetic, multiplicative and accretionary. The human growth curve is sigmoid and is controlled by hormones. Regeneration is of two types...

;). For Balmer series, n 1 = 2, n 2 = 3,4,5,… For Paschen series, n 1 =3, n 2 = 4,5,6… For Brackett series, n 1 = 4, n 2 = 5,6,7…. For P fund series, n 1 = 5, n 2 = 6,7,8…. Total energy of an electron in a stationary orbit is calculated from the relation Atomic masses ar..

(the collection of genes) will be inherited by successive generations. Darwin proposed the theory of natural selection. According to this theory, the reproduction in large numbers resulted in a struggle for existence and competition. This leads to survival of the fittest. Thus the best of the genet..

Asia has 60% of global population and continues to dominate the global population in next 50 years. Some countries in Europe have negative or zero growth of population. In India, U.P is a populous state but density of population is highest in West Bengal, literacy rate and sex ratio is high..

) or secretory products (gums, alkaloids, hormones, etc) or excretory products (calcium carbonate and other salts). These substances are generally stored in the vacuoles. Cell organelles are mainly of two types membrane-bound and non-membranous. Membrane bound organelles include endoplasmic reticul..

>Law of conservation of energy states that the total energy of an isolated system cannot change. A collision is said to take place when either two bodies physically collide against each other or when the path of one body is changed by the influence of the other body. A collision is said to be an el..

Chromosomes are tiny thread-like structures found in the nucleus of a cell. Chromosomes store and transmit the coded information which is responsible for all the life processes of an organism. Hence, chromosomes are commonly described as carriers of heredity. In bacteria, the entire heredit..

Endocrine system consists of many endocrine or ductless glands, which secrete hormones into the blood. Hormones are information molecules, which regulate specific physiological processes in the target cell, tissues or organs. Hormones co-ordinate the activities of different organs and tissu..