CLASS VII Chapter 5 : Acids, Bases and Salts
 Fill in the blanks :
 1. Spinach contains_____________ acid while tamarind contains ________________ acid.
2. The gas which escapes out from many aerated soft drink is _____________
3. Carbon burns in air to form _______________
 4. The chemical name of lime water is ______________
 5. _______________ is the reaction between an acid and base.
6. An aqueous solution of sodium oxide changes ________________ litmus to blue.
7. Phenolphthalein indicator turns acidic solutions to ______________ and basic solutions to _____________.
 8. The chemical name of moist baking soda is _____________
 9. Calamine solution contains __________________( a base ).
 10.Litmus is obtained from the _____________________
 11.Curd contains __________ while vinegar contains ___________

 Complete the following word equations : 
1. Zinc + hydrochloric acid                                                       ___________+ _____________
 2. Sodium hydroxide + Hydrochloric acid                               ___________+ ________
3. Calcium hydroxide + sulphuric acid                                            _____________+ ________

True or False :                        
1. All acids turn blue litmus red. True / False
2. Neutral solution can change the colour of litmus. True / False
 3. Orange juice turns blue litmus red. True / False
 4. Substances which are neither acidic nor basic are called neutral. True/ False
 5. An acid and a base neutralize each other and from a salt. True / False.
 6. China rose indicator turns acidic solution to green. True / False

 Name the following :
 1. Two natural indicators.
2. One artificial indicator
3. Two pollutants in the air which causes acid rain
. 4. Two substances which can neutralize an ant’s bite.
 5. Two acids found in citrus fruits

. Define 1. Indicators 2. Neutral solution

 Chapter 6: Physical and Chemical Change
 Fill in the blanks:
1. Changes that lead to the formation of new substances are called ________________
 2. Melting of candle wax is a______________ change but its burning is a ______________ change. 3. Growth of a plant is a ____________ change while formation of clouds is a _____________ change.
 4. A brown layer formed when an iron article is left exposed in air in an open area is called ___________
 5. Large crystals of pure substance are obtained by ____________
_ 6. The brown layer deposited on an iron nail dipped in copper sulphate solution is due to

CLASS -VII REVISION WORKSHEET
Chapter 4: Heat
 Fill in the blanks 
: 1. ______________ is a device used for measuring temperature

. 2. The materials which allow heat to pass through them easily are __________ of heat.
 3. Clinical thermometer is used to measure our _____________
 4. Wool is poor __________________ of heat and it has air trapped in between the fibres.
 5. In ______________ generally the heat is transferred by conduction.
 6. _______________ metal is used in the bulb of the thermometer.
7. The normal temperature of the human body is __________

 True or False :
 1. The materials which do not allow heat to pass them easily are called insulators.
 2. In liquids and gases the heat is transferred by conduction.
3. A kink near the bulb of a clinical thermometer prevents mercury level from falling of its own
. 4. We get heat from the sun by radiation.
5. Digital thermometers contain mercury.

Define : 1. Temperature 3. Conduction 2. Radiation 4.Convection
 Name the following:
 1. The movement of cool air from land towards sea.
 2. Two conductors of heat
3. Two insulators of heat

 Distinguish between  Conductors and insulators.
  Clinical and laboratory thermometer

 Diagram  Clinical Thermometer Laboratory Thermometer. 

CLASS VIII REVISION WORKSHEET
LESSON-LIGHT
Give one word for the following : 1. The invisible energy which causes in use the sensation of vision. 2. The ray of light which travels towards a mirror.
 3. A line which is drawn at right angles to the mirror surface at the point of incidence.
 4. Name one type of mirror which always form virtual image.
 5. What type of image is formed on the cinema screen ?
 6. Which cells on the retina respond to the intensity of light.
 7. The part of the eye which preserves its shape and protects it from external injuries.
 8. The phenomenon due to which we can judge depth.
9. The most sensitive part of the retina.
Fill in the blanks : 1. The point at which the incident ray falls on the mirror is called ___________________
 2. If a ray of light is incident on a plane mirror at an angle of 300 , its angle of reflection is _______________.
 3. If a ray of light is incident normally on a mirror, i = __________ and r = ________________ 4. The image of our face in a plane mirror is an example of ___________ image.
5. The distance of the image behind the plane mirror is _________ to the distance of the object in front of it.
 6. The principle of ___________is made use of in motion picture projection in cinematography.
 7. The presence of __________________ cells on the retina helps us to see in dim light
. 8. The coned shaped cells of our retina respond to _____________
 9. Due to the absence or insufficient number of ____________ cells a person becomes colour blind. 10. Owls and bats are able to see at night due to the presence of ______________ cells in their retina. 11. The thin, saline liquid that fills the anterior part of the eye is _________.
12. ___________ is the jelly like fluid found in the posterior part of the eye.
 13. In a spectrum formed by a prism ______ colour deviates the least and ____________ colour deviates the most.
 Multiple choice questions :
 1. The scientist who discovered that white light is composed of 7 colours
. [ Louis Braille, Dalton, Issac Newton]
 2. _____________________ can be donated after death, to enable a blind person see. [ optic nerve, cornea, iris]
 3. The part of the retina which is insensitive to light. [ cornea, yellow spot, blind spot]

4. Focal length of the eye lens can be adjusted by the action of [ choroid, ciliary muscles, optic nerve] 5. Formation of multiple images in the eyes is avoided by the action of [iris, pupil, choroid]
 6. The colour of a person‟s eye is determined by his [pupil, iris, retina]
 7. Electric pulses from retina to brain is conveyed through [ciliary muscles, optic nerves, pupil]

                                 CLASS-IX REVISION WORKSHEET
                                 ATOMS AND MOLECULES

1. Name the scientist who gave two important laws of chemical combination.

2. What is law of conservation of mass? Describe with an activity.

3. State the law of constant proportion. Give example.

4. Write the postulates of Dalton’s atomic theory.

5. What is the difference between 2N and N2?

6. What is the difference between an atom and molecule?

7. If 100g of water is decomposed, how many grams of oxygen and hydrogen are obtained?

8. Write symbols of: (a) copper (b) mercury (c) iron (d) silver (e) gold (f) argon (g) zinc (h) cobalt (i) lead (j) potassium (k) silicon

9. What is meant by valency of an element?

10. Give two examples each of:

(a) Mono atomic molecule (b) tri atomic molecule (c) Di atomic molecule (d) poly atomic molecule

11. Write the chemical formula of: (a) Sodium oxide (b) calcium chloride (c) aluminium oxide

(d) magnesium hydroxide (e) sodium carbonate

12. Find the mass of:(a) .2 moles of oxygen gas (b) 1.5 moles of water (c) 3 moles of neon

(a) .5 moles of sodium (e) 2 moles of nitrogen element

13. Find the molecular mass of:

(a) H2S (b) HCl (c) NH3 (d) Cl2 (e) CH3COOH (f) CH3CHO

14. How many moles are there in 200 g of Na?

15. Calculate the mass of 1 atom of nitrogen?

16. How many molecules are present in 10 g of H2O?

17. Find the formula unit mass of: (a) NaCl (b) FeO (c) NaHCO3 (d) CuSO4

CLASS 8
DEFECTS OF VISION

class 8

CHAPTER-LIGHT 

REVISION WORKSHEET
CLASS 9

1.What is atomic mass unit?
2.Determine the valency of the given elements.
(i) Chlorine (17) (ii) Sulphur (16)(iii) Aluminium(13)
3.with example explain the law of constant propotion.
4.Na+ has completely filled K and L shells.Explain
5.give uses of any three isotopes
6.An element has atomic number 12 and atomic mass 26. draw a diagram to show the distribution of electrons in the orbits and the nucleus composition of the element. what is the valency of the element.
7.What are isobars? Give one example
8.Write the chemical formulas of the following compounds
(i) Aluminium nitride
(ii)Ammonium phosphate
9.calculate the no.of moles in 32g of oxygen gas.
10.Determine the molecular mass of CaCO3 and Al(OH)3
11.write the postulates of Bohr's Model of an atom.
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