EARTH MATTER

OCCURRENCE IN EARTH 

➤ Earth is a rich source of elements, found either in native state or in compound form. 

➤ The solid phase of the earth is called the lithosphere. 

➤ Percentage distribution of elements in earth’s crust is as shown below : 

                    ➤ Ocean and seas, which form major component of hydrosphere, are again vast reservoirs of elements.

                   ➤ The major elements are Chlorine, Sodium, Magnesium, Sulphur, Calcium, Potassium and Carbon in that order. 

                   ➤ The minor elements are Bromine, Boron, Strontium, Silicon, Nitrogen, Lithium, Aluminium and Rubidium. 

                    ➤ Four elements, Chlorine, Bromine, Sodium and Magnesium

                    ➤ Manganese nodules found in the sea bed may form a potential source of some of the less common metals. 

                    ➤ The gaseous phase of the earth is called atmosphere.

                   ➤ The atmosphere mainly consists of nitrogen (78.09%), Oxygen (20.95%). Argon (0.93) and other gases (<1%). These gases are obtained by fractional distillation of air. 

                     ➤ Carbon dioxide forms about 0.04% of the atmosphere. 

                     ➤ Ozone exists mostly at the outer atmospheric level, where it helps in the absorption of solar ultraviolet radiation. Therefore, ozone is considered as chemical weed. On earth surface it is bluish toxic gas but in stratosphere, it is useful in protecting earth from UV-rays. 

                  ➤ Examples of elements accumulated in living organisms are : 1. Iodine in sea weeds 2. Vanadium in sea cucumbers 3. Potassium in plant leaf 

                  ➤ Examples of elements concentrated in different parts of living beings are : 1. Iron (Fe-11) in blood 2. Zinc in the eyes of certain animals 3. Magnesium in chloroplast 4. Copper in mollscus have blue colour fluid (blood) because copperions.

The VEDA & It's Classification as well as Important

RIG VEDA 

➤ It is divided into 10 Books or Mandalas. Books II to VII are considered the oldest. Book I, VIII and X seem to be later additions.

 ➤ A collection of 1028 hymns of a number of priestly families.

 ➤ Written between 1700-1500 B.C. when Aryans were still in Punjab.

➤ The IX mandala is dedicated exclusively to Soma.

 ➤ The singer of the Rigveda is called the Hotra. 

➤ The X Mandala contains the famous Purushsukta hymn that explains the origin of four Varnas.

 ➤ Gayatri Mantra is the most sacred hymn of Rig Veda. Mentioned in 3rd mandal, written by Viswamitra. 

YAJUR VEDA 

➤ A ritualistic Veda. It is divided into Shukla Yajurveda and Krishna Yajurveda. Written in prose, it deals with procedure for performance of sacrifices and contains rituals as well as hymns. The singer of the Yajur Veda is called Ardhavayu.

 SAMA VEDA ➤ Sam Veda derives its roots from Saman, which means a melody. A collection of melodies. A collection of 1603 hymns. Except 99, all other were derived from Rig Veda. It contains the Dhrupada Raga. The singer of Sama Veda is called Udgata.

  ATHARVA VEDA ➤ A collection of 711 hymns, it is divided into 20 khandas. It is the latest Veda. Atharva Veda is a book of magical formula medicinal treatises etc. It contains charms and spell to ward off evil and disease. Its content throws light on the practices of non Aryans. In Atharvaveda, Sabha and Samiti are described as uterine sisters–The two daughters of Prajapati. This veda is also known as Brahma Veda. 

Upanishadas ➤ The Upanishadas are philosphical texts. They are generally called Vedanta, as they came towards the end of the Veda. There are 108 Upanishadas. Vrihadaranyaka is the oldest Upanishada. Literature of Vedic Tradition (600 BC-600 AD)

 ➤ Literature of Vedic Tradition (Smriti i.e. rememberance literature) comprises of 6 literary works : 1. Vedangas/Sutras 2. Smritis Dharmashastras 3. Mahakavyas (Epics) 4. Puranas 5. Upvedas 6. Shad Dharshanas.

 ➤ There are six Vedangas :

(i) Shiksha (Phonetics): Tratishakhya’- the oldest text on phonetics. 

(ii) Kalpa Sutras (Rituals): (a) Shravta Sutras/Shulva Sutra – deal with the sacrifices, (b) Grihya Sutras—deal with family ceremonies, (c) Dharma Sutras—deal with Varnas, Ashramas etc. 

(iii) Vyakarana (Grammar) : ‘Ashtadyayi’ (Panini) — oldest grammar of the word. (iv) Nirukta (Etymology): ‘Nirukta’ (Yask) based on ‘Nighantu’ (Kashyap)— a collection of difficult vedic words—(‘Nighantu’— the oldest wordcollection of the-world; ‘Nirukta’—the oldest dictionary of the world). (v) Chhanda (Metrics): ‘Chhandasutras’ (Pingal)–famous text. (vi) Jyotisha (Astronomy) ‘’Vedanga Jyotisha’ (Lagadh Muni – the oldest Jyotisha text.

 ➤ There are six famous smritis: (i) Manu Smriti (Pre-Gupta Period)— the oldest Smriti text; Commentators : Vishwarupa, Meghatithi, Gobindraj, Kulluk Bhatt. (ii) Yajnavalkya Smriti (Pre-Gupta Period)— Commentators : Vishwarupa, Vijayaneshwar, Apararka (a king of Shilahar Dynasty) (iii) Narad Smriti (Gupta period),