1.Which of the following are homogeneous in nature? (i) ice (ii) wood (iii) soil (iv) Air
2. A standard sheet of paper is about atoms thick.......
3. One dot that you make with your pen has more than ______ lakh molecules.
4. Pure rava, when adultered with wheat flour, is separated by
5. Lighter impurities like dust, when mixed with rice or pulses, can be removed by _____
6. Which among the following is not a matter?
7. Filtration method is effective in separating _____ mixture.
8. Evaporation of water from lakes and river
9. _______ change is a temporary change
10. The blackening of the Silver anklet is a (an)
11. Formation of coal is a …………
12. Out of the following an example of a desirable change is
13. When ice melts to form water, change occurs in its
14. Air pollution leading to Acid rain is a
15. Magnet attracts iron needle. This is ……… change
16. Boiling of egg results in ………… change
17. Plants convert Carbon-di-oxide and water into starch. This is an example of ………. change
18. Burning of match stick is a
19. ……… is the percentage of nitrogen in the air.
20. A layer consisted of water vapour which is responsible for making clouds is.
21. _______ was able to identify highly reactive gas called oxygen.
22. Which is used in refrigerating meat and fish?
23. A process without emitting flame is called as …………
24. _______ is responsible for making clouds.
25. The Ozone layer is present in
26. Inhaled air contains a large amount of
27. The composition of air is always exactly the same.
28. Carbon dioxide (CO2) gas turns lime water milky.
29. The molecular formula of Epsom is _______
30. _______ are the substances which can undergo chemical changes to produce certain materials.
31. ………. to remove strong strains on the clothes.
32. All the plants get their _______ from the soil.
33. If 50 kg of Superphosphate is added to the soil, how much phosphorus would the soil get?
34. ……….. are necessary for soap preparation.
35. ………..is called a farmer’s best friend.
36. Gypsum is added to the cement for ………..
37. Soaps were originally made from ………
38. The saponification of a fat or oil is done using _______ solution for hot process.
40. Natural adhesives are made from ………..
41. The balance of oxygen in the atmosphere is maintained through Photosynthesis in plants & respiration in animals
42. Plaster of Paris is obtained from heating gypsum.
43. What are the ingredients of the cement?
44. -----------gets compressed easily
45. ---------- bends readily
46. When pulses are washed with water before cooking, the water is separated from them by the process of Decantation.
47. Gypsum is added to control the setting of cement.
48. What will happen if we remove plants from the aquarium?
49. What will happen if you breathe through your mouth?
50. The two types of molecules found in the soap are
