STUDY EDUCATION - MP Board Solutions

NCERT Class 8 Science Chapter 6 Combustion and Flame Solutions NCERT TEXT BOOK EXERCISES Q. 1. List the conditions under which combustion can take place. Ans. Conditions for the combustion: 1. The presence of a combustible substance. 2. The presence of a supporter of combustion. 3. Initial heating to bring the combustible substance to its ignition temperature. Q. 2. Fill in the blanks: (a) Burning of wood and coal causes _________of air. Ans. Pollution. (b) A liquid fuel, used in homes is __________. Ans. Kerosene. (c) Fuel must be heated to its ___________ before it starts burning. Ans. Ignition temperature. (d) Fire produced by oil cannot be controlled by __________. Ans. Water. al Resources Q. 3. Explain how the use of CNG in automobiles has reduced pollution in our cities. Ans. The use of CNG in automobiles has reduced air pollution in our cities in following ways: (i) It produces less amount of carbon monoxide gas. (ii) It produces less amount of carbon dioxide gas. (iii) It produ...

NCERT Class 8 Science Chapter 5 Coal and Petroleum Solutions NCERT TEXT BOOK EXERCISES Q. 1. What are the advantages of using CNG and LPG as fuels? Ans. Advantages of LPG as fuel: (i) LPG has a high calorific value. Its calorific value is about 50 kJ/g. (ii) It burns with a smokeless flame and so does not cause any pollution. (iii) LPG is easy to handle and convenient to store. (iv) It undergoes complete combustion. Advantages of CNG as fuel: (i) It does not cause air pollution. (ii) It leaves no ash on burning. Q. 2. Name the petroleum product used for surfacing of roads. Ans. Bitumen. Q. 3. Describe how coal is formed from dead vegetation. What is this process called? Ans. Formation of coal from dead vegetation: About 300 million years ago, there were dense forests in the wet lands that got buried under the surface of the earth due to some environmental changes such as earthquakes, volcanoes and flooding. Gradually, they were covered with many layers of soil and got decomposed. The ...

NCERT Class 8 Science Chapter 4 Materials: Metals and Non-Metals Solutions NCERT TEXT BOOK EXERCISES Q. 1. Which of the following can be beaten into thin sheets? (a) Zinc. (b) Phosphorus. (d) Oxygen. (c) Sulphur. Ans. (a) Zinc. Q. 2. Which of the following statements is correct? (a) All  metals are ductile. Ans. ×. (b) All non-metals are ductile. Ans. ×. (c) Generally, metals are ductile. Ans. ✓.  (d) Some non-metals are ductile. Ans. ×.  Q. 3. Fill in the blanks: (a) Phosphorus is very __________ non-metal. Ans. Reactive. (b) Metals are __________ conductor of heat and __________. Ans. good, electricity . (c) Iron _________ reactive than copper. Ans. less. (d) Metals react with acids to produce _________ gas. Ans. hydrogen. Q. 4. Mark ‘T’ if the statement is true and ‘F’ if it is false: (a) Generally, non-metals react with acids. Ans. F. (b) Sodium is a very reactive metal. Ans. T. (c) Copper displaces zinc from zinc suphate solution. Ans. F. (d) Carbon can be drawn int...