Adegree is angstroms it is 10^-10 where as AU is astronomical unit distance between sun and earth 15 crore km

(a) Heterotrophic bacteria

(1) Many bacteria like Lactobacillus helps in the production of curd from milk.

(2) They act as decomposers and help in the formation of humus e.g. Pseudomonas.

(3) Many antibiotics are obtained from some species of bacteria like streptomyces, Bacillus etc.

(4) Many soil bacteria help in fixation of atmospheric nitrogen like Rhizobium (Symbiotic), Azotobacter (Free living).

(b) Archaebacteria

(1) Methane gas is produced from the dung of ruminants by the methanogens.

(2) Methanogens are also involved in the formation of biogas and sewage treatment.

Government publications 

Reports of committees and commissions

Publications of research scholars.

Economics is a study of mankind in the ordinary business of life; it examines that part of individual and social action which is most closely connected with the attainment and with the use of the material requisites of well-being.
 

Mourad kicked his feet into the horse and screamed: "Vazire run!" The horse endured on its back legs snorted and move ahead at full pace. Mourad rushed the horse beyond a range of dry prairie to an irrigation channel. He traversed the channel on the horse. While he returned five minutes later he was dripping moist.

अर्थशास्त्र की विषय-वस्तु आर्थिक इकाइयों का आर्थिक व्यवहार है जो वे व्यक्तिगत रूप में अथवा समूहों के रूप में करती है। अर्थशास्त्र की विषय-वस्तु को मुख्य रूप से दो भागों में बांटा जाता है:

1. व्यष्टि अर्थशास्त्र
2. समष्टि अर्थशास्त्र

1. व्यष्टि अर्थशास्त्र: व्यष्टि अर्थशास्त्र में व्यक्तिगत आर्थिक इकाइयों के व्यवहार का अध्ययन किया जाता है, जैसे एक उपभोक्ता, एक गृहस्थ, एक उत्पादक तथा एक फर्म इत्यादि।
2. समष्टि अर्थशास्त्र: समष्टि अर्थशास्त्र में संपूर्ण अर्थव्यवस्था के स्तर पर आर्थिक समस्याओं अथवा आर्थिक समूहों के व्यवहार का अध्ययन किया जाता है; जैसे राष्ट्रीय आय, रोज़गार, सामान्य कीमत स्तर आदि।

विशिष्ट अर्थशास्त्र और समष्टि अर्थशास्त्र में अध्ययन किए जाने वाले विषय निम्नलिखित है:

(i) Gram atomic mass of Au= 197 g 

Or

197g of Au contains = 6.022 x 10²³

Therefore 1gm of Au contains = 6.022 x 10²³/197*1 = 3.06 x 10²¹ atoms

(ii) Gram atomic mass of Na = 23 g

Or

23 g of Na contains atoms = 6.022x 10²³

Or

1gm of Na contains atoms = 6.022x10²³ /23 *1 = 26.2 x10²¹atoms

(iii) Gram atomic mass of Li = 7

Or

7g of Li contains atoms = 6.022 x 10²³

Or

1g of Li contains atoms = 6.022 x 10²³/7 *1= 86.0 x 10²¹ atoms

(iv) Gram atomic mass of Cl = 71 Or 71g of Cl contains atoms = 6.022x10²³

Or

1 g of Cl contains atoms = 6.022x10²³ /71 * 1= 8.48 x 10²¹atoms

Economy is the state of a country or region in terms of the production and consumption of goods and services and the supply of money.

Dipole-Dipole interactions result when two dipolar molecules interact with each other through space. When this occurs, the partially negative portion of one of the polar molecules is attracted to the partially positive portion of the second polar molecule. This type of interaction between molecules accounts for many physically and biologically significant phenomena such as the elevated boiling point of water.

The decline of the handicraft industry in India resulted in massive unemployment and a rise in demand for Britain's manufactured goods.

•  Hominid is one of the member of the biological family called Hominidae on the other hand Monkeys are non Hominoid.
•  Hominids does not possess tail on the other hand monkeys possess tail.

Check summary in the notes : https://mycbseguide.com/cbse-revision-notes.html

Physical geography includes the study of lithosphere (landforms, drainage, relief and physiography), atmosphere (its composition,structure, elements and controls of weather and climate; temperature, pressure, winds,precipitation, climatic types, etc.),hydrosphere(oceans, seas, lakes and associated features with water realm) and biosphere ( life forms including human being and macro-organism and their sustaining mechanism, viz. food chain, ecological parameters and ecological balance).

The study of physical geography is emerging as a discipline of evaluating and managing natural resources. In order to achieve this objective, it is essential to understand the intricate relationship between physical environment and human beings. Physical environment provides resources, and human beings utilise these resources and ensure their economic and cultural development. Accelerated pace of resource utilisation with the help of modern technology has created ecological imbalance in the world. Hence, a better understanding of physical environment is absolutely essential for sustainable development.