Carbon and its compounds

Carbon is the common element found in all known form of life. Structure of all living organism contains carbon. Carbon present in living organism even after death. Coal, petroleum and its products are compounds of carbon. Carbon is an element and a non-metal. Symbol of Carbon = C Atomic number of carbon = 6 Atomic … Read more

Fundamental unit of life-Cell

  Objects having characteristics of cellular organization, growth, reproduction, ability to sense environment and give response are living organisms. There are some important features of living organisms: It should grow, which means its structure changes as time goes by in an advantageous manner. It should show adaptation to the environment. It should maintain some balanced … Read more

Reproduction

Reproductive systems The reproductive system in both males and females consists of structures that produce reproductive cells, or gametes, and secrete sex hormones. A gamete is a haploid cell that combines with another haploid gamete during fertilization. Sex hormones are chemical messengers that control sexual development and reproduction. The male reproductive system consists of structures … Read more

Heredity and Evolution

Evolution, simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations). Evolution helps us to understand the history of life. Evolution is not simply a matter … Read more

Gravitation

Newton’s law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Gravitation Gravitation is the force by which every mass or particle of matter, including … Read more

Motions, Force, Laws of Motion

Motion Motion is a change in position of an object with respect to time. Motion is typically described in terms of displacement, distance, velocity, acceleration, time and speed. The branch of physics which deals with the study of motion of material objects is called mechanics. Mechanics is divided into following branches. (i) Statics : Statics … Read more

Percentage

Important Formulas – Percentage PercentagePercent means for every 100 So, when percent is calculated for any value, it means that we calculate the value for every 100 of the reference value. percent is denoted by the symbol %. For example, x percent is denoted by x% x%=x/100Example : 25%=25/100=1/4 To express x/y as a percent, we have x/y=(x/y×100)%Example … Read more

Discount

The discount is referred to the reduction in the price of some commodity or service. It may anywhere appear in the distribution channel in the form of modifications in marked price (printed on the item) or in retail price (set by retailer usually by pasting a sticker on the item) or in list price (quoted for the buyer). The discount is provided for the … Read more

Compound Interest

Compound Interest   Let Principal = P, Rate = R% per annum, Time = n   When interest is compound Annually:    Amount = P 1 + R n 100 When interest is compounded Half-yearly:     Amount = P 1 + (R/2) 2n 100 When interest is compounded Quarterly:     Amount = P 1 … Read more