Chitwan National Park, the oldest national park in Nepal, is situated in the subtropical inner Terai lowlands of south-central Nepal. It covers 932 square kilometers. It offers a wilderness of rich ecosystem that includes mammals, birds, reptiles and water animals of several kinds. The park was declared UNESCO Heritage Site in 1979 owing to its rich adornment of nature. The park covers a pristine area with a unique ecosystem of significant value to the world. It contains the Churiya hills, Ox-bow lakes and flood plains of Rapti, Reu and Narayani Rivers. There are around 600 plant species, 50 mammals, 526 birds and 49 amphibians, reptiles found in the park.

The park is specially renowned for the endangered one-horned rhinoceros, the tiger and the gharial crocodile along with many other common species such as gaur, wild elephant, four-horned antclope, striped hyena, pangolin, Gangetic, dolphin, monitor lizard and Python. Other animals found in the park include the sambar, Chital, Hog deer, Barking dear, Sloth Bear, Palm civet, Langur and Rhesus monkey. The forest is alive during summer with the arrival of migrant birds, paradise flycatcher, Indian pitta and parakeets, which winter birds include Waterfowl, Barminy ducks, Pintails, Bar-headed geese, Cormorants and migratory birds from Siberia. A rare attraction of the park is the world's fresh water dolphin variety sometimes seen in River Narayani. The park is being the centre of scientific studies of several species of wild flora and fauna.It is famous for one horned rhinoceros and Wild Buffaloes. Spiny Babbler , the only bird found in Nepal is also probably found in it.

Depending upon the shape, volume and rigidity, matter can be classified into three states, viz. solid, liquid and gas.

Science is the study of nature and its application to mankind, Chemistry is a branch in which we study about the composition, structure and properties of matter and the changes which matter undergoes by the interaction of its various forms. Our universe is composed of matter and energy. Matter may, thus, be defined as anything that occupies space, possesses mass, offers resistance and can be felt by one or more of our senses. Some examples mass, offers resistance and can be felt by one or more of our senses. Some examples of matter are water, air, metals, plants, animals, etc. Thus, matter has countless form. Matter can be classified into different categories depending upon its physical or chemical nature.

The amount of matter present in any object is called its mass and the forces with the object is pulled towards the centre of earth is its weight. Closely related to matter is energy. It is defined as the capacity of a body to do work. Energy is different from matter because it cannot be seen, touched or smalt. However, it can be observed by its effect on matter.

Life is a unique and complex phenomenon that distinguishes the living organisms from non-living things or inanimate things. The origin of life in the universe is one of the most complicated problems for the biologists. The problem of creation resolves itself into two aspects: the origin of the forms of life and origin of life itself. Different biologists have proposed different theories concerning the origin of life. The major theories accounting for the origin of life are: