Points from 6th Std SSC Science book – For Homibhabha Exam

A few points from the 6th Std SSC board science textbook: (Useful only from Exam point-of-view, NOT from scientific point-of-view!)

PHYSICS

  1. The energy resources which do not produce smoke and carbon gases such as carbon dioxide or carbon monoxide are called ‘Green energy resources’.
  2. Sound is propagated more clearly through liquids than through air. Most clearly through solids.
  3. Birds like the robin and the woodcock can recognize the sound of an earthworm in the soil, and find their prey
  4. Some species of grasshopper produce a sound by rubbing their legs together while flying in the air.
  5. Some anglerfish as well as honey mushroom are natural sources of light.
  6. The largest sundial is at Jantar Mantar, New Delhi.
  7. National Science Day’ 28th February beause. Raman discovered his Effect ‘regarding scattering of light’ on that day
  8. Milky Way. = Mandakini.
  9. Variable Stars (Polaris) : The luminance and shape of these stars is not stable. They are constantly contracting or expanding. When a star expands, its brightness decreases. When contracts, its surface temperature increases and appears brighter.
  10. Mercury is the fastest moving planet.
  11. The highest and longest mountain in the solar system ‘Olympus Mons’ is located on Mars.
  12. Rotation time of moon = 27.3 days
  13. Long period comets have period more than 200 yrs. Short period – less than that.

CHEMISTRY

  1. Water is 71% and land is 29% on Earth
  2. Troposphere contains about 80% of the total mass of gases. 19% in the stratosphere
  3. Helium – Used for obtaining low temperature and also for generating lift in airships.
  4. Krypton – Used in fluorescent tubes.
  5. Xenon – Used in flash photography
  6. Ozone (O3) gas in the lower part of stratosphere. ozone is destroyed by carbon tetrachloride or the chlorofluorocarbons used in refrigerators. World ozone day- 16 Sept
  7. Boiling of water is called ebullition.
  8. Nylon, dacron, terylene, terene, polyester, rayon, acrylic are the names of various synthetic threads.
  9. Rayon: Cotton and wood pulp is dissolved in a chemical called sodium hydroxide to make a solution. It is called synthetic silk

BIOLOGY

  1. It takes about a thousand years for a 2.5 cm thick layer of mature soil to form.
  2. The proportion of humus in the upper layer of good fertile soil is about 33% to 50%.
  3. lifespan of the mayfly ranges from 1 hour to 24 hours
  4. In case you find an unfamiliar plant or animal in our surroundings you can communicate with these institutes to obtain information about it Botanical survey of India and zoological survey of India
  5. Vasaka (adulsa), hirada, behada, asparagus are used as medicines.
  6. Some plants, too, can be harmful, as for example, the dodder, parthenium and other weeds.
  7. Pods of the nettle, colocasia leaves cause itching.
  8. Plants like oleander, lantana have strong odours.
  9. The datura plant is poisonous.
  10. Carolus Linnaeus made the first scientific classification of plants
  11. The oleander, hibiscus, lantana, koranti and rose are shrubs that may grow up to two to three metres.
  12. vines like the pumpkin, the railroad creeper, kavali, watermelon or the grapevine
  13. The world’s smallest flower is of the plant called Wolffia or duckweed. Its diameter is as small as 0.5 mm.
  14. In 1993, many people died due to the earthquake at Killari in Latur district
  15. In July 2014, the whole village of Malin in Ambegaon taluka of Pune district was destroyed in a matter of minutes due to a landslide.
  16. November 2015, many people died due to the flooding caused by heavy rains in Tamil Nadu.
  17. When we work in the sun continuously for a long time, the body loses a lot of water and minerals. That is the reason for sunstroke.
  18. cobras, kraits, vipers and sea snakes are poisonous
  19. In the 19th century, the scientist J. Willard Gibbs showed that the characteristic properties of a substance depend on its physical state and the arrangement of particles in it.
  20. Liquid nitrogen is used in animal husbandry.
  21. Charles Goodyear Vulcanization of rubber – tyres
  22. rubber tree – Hevea brasiliensis’. originally from brazil
  23. paper is a kind of network of cellulose fibres.Coniferous trees like pine are used to make paper.
  24. In Maharashtra, there is a paper factory at Ballarpur near Chandrapur
  25. Children of growing age need to get approximately 2000 to 2500 Calories
  26. Casimir Funk discovered = people who ate brown rice were less likely to get beriberi He was able to identify and isolate the substance which prevents this disease. He named it ‘vitamine’.
  27. The food pyramid helps us to choose a balanced diet.
  28. Junk food gives us energy but not other nutrients.
  29. ‘X-rays’ were discovered by Wilhelm Conrad Roentgen.
  30. Bones of our body are classified into four types: Flat, Small, Irregular (Vertebra), Long
  31. 22 bones in the skull, 8 in the head and 14 in the face.
  32. Twelve pairs of flat bones called ribs and sternum. = 25 bones form the rib cage
  33. The spine is formed by 33 padlock-shaped bones
  34. stirrup is the smallest bone. longest femur.
  35. The bones in our body are connected to each other by means of ligaments
  36. The outermost layer of skin is epidermis and the layer below that is dermis. Below that is subcutaneous layer or hypodermis.
  37. As we grow older, the proportion of fat beneath the skin reduces. This causes wrinkles.
  38. Jet black hair is due to pure melanin, while brown, lighter hair is due to sulphur in the melanin and reddish hair, due to iron in the melanin.
  39. From one silk cocoon, 500 metres to 1300 metres of thread can be obtained.
  40. The botanical name of rubber tree is ‘Hevea brasiliensis
  41. Earlier irlis or capes made of grass or sackcloth were used for protection from rain.
  42. Natural substances used to write: Tree bark, leaves, bhurjpatre, pens made from reeds, dhulpatya, stone slates, stone walls in caves, soil and colours made from plants.