KENDRIYA VIDYLAYA NEW CANTT ALLAHABAD
Periodical Test -1
Sub- Science MM-40
TIME-90 MIN CLASS-VIII
INTRUCTIONS:
1. All questions are compulsory.
2. Marks allotted against each question.
MCQ (1*3= 3)
1. Seed drill is used for
a- harvesting b- cleaning
c- Sowingd- weeding
2. Yeast is used in the production of
a- sugarb- alcohol
c- Hydrochloric acidd- oxygen
3. The process of conversion of sugar into alcohol is called
a- Nitrogen fixationb- moulding
c- Fermentationd- infection
4. Define animal husbandry. 1
5. What is combine? 1
6. Draw a diagram of virus. 2
7. Define biodegradable substances. Write two examples. 2
8. Explain the difference between thermoplastic and thermosetting plastic. 2
9. DEFINE : 2
(a)combustion (b) ignition temperature.
10. What is coke? Write its two uses.2
11. What are antibiotics? What precautions must be taken while taking antibiotics? 3
12. Write a short paragraph on the harms caused by microorganisms. 3
13. Why Sodium and potassium are stored in kerosene? 3
14. What are the advantages of using CNG and LPG as fuels? 3
15. Describe how coal is formed from dead vegetation. What is this process called? 3
16. Write down the five differences between fertilisers and manures. 5
17. What happens when 5
(a) Dilute sulphuric acid is poured on a copper plate
(b) Iron nails are placed in copper sulphate solution
Write word equations of the reactions involved.
…….x…….x…..x……x……x……
MARKING SCHEME
VLASS-VIII
SUB= SCIENCE
1.SOWING
2. ALCOHOL
3.FERMENTATION
4. Rearing of useful animals on commercial scale.
5.Machine having combined harvester & thresher.
6.diagram of virus fig.2.5 ,page no.19 of NCERT BOOK.
7.Decomposing of materials through natural processes.eg.vegetables peels, paper or any other
8.Thermoplastics: Deformed easily by heating,can be bent easily.
Thermosetting plastics: can not be soften easily by heating,can not bent.
9. Combustion: Chemical process in which a substance reacts with oxygen to give off heat
Ignition temperature: Lowest temperature…..a substance catches fire.
10.Atough,porous, black substance obtained from coal.manufacturing of steel,extraction many metals.
11.Antibiotics: medicines to kill or stop growrh of microorganisms.
Make the drugs less effective , may kill useful bacteria
12.Micro. …harmful…..cause diseases…..inhumans,plants,animals……..pathogens….spoil food….clothing & leather……
13.Reacts vigorously with oxygen&water
14.They are less polluting,cleanerfuelcan be used direcly at homes
15.About 300 millions …. Dense forest…..wetland……were compressed …..temperature ….high pressure……converted ….coal.
Carbonisation.
16.five differences in each.
17.(a)Copper sulphate,hydrogen gas.
Copper +sulphuric acid=copper sulphate +hydrogen gas
(b)deposit brown coat
Iron+ copper sulphate= iron sulphate +copper
X …… x….. xxxxx……..