Which of the following statements is correct?
(a) All metals are ductile.
(b) All non-metals are ductile.
(c) Generally, metals are ductile.
(d) Some non-metals are ductile.
(c) Generally, metals are ductile
Generally metals are ductile but some exceptions are there like mercury is a metal which is liquid at room temperature. It cannot be drawn into wires, so it is not ductile.
Can you store lemon pickle in an aluminium utensil? Explain.
Which of the following can be beaten into thin sheets?
(a) Zinc (b) Phosphorus (c) Sulphur (d) Oxygen
Fill in the blanks :
(a) Phosphorus is very _________ non-metal.
(b) Metals are ________ conductors of heat and ________ .
(c) Iron is __________ reactive than copper.
(d) Metals react with acids to produce _________ gas.
In the following Table some substances are given in Column I. In Column II some uses are given. Match the items in column I with those in Column II.
Column I | Column II |
---|---|
(i) Gold (ii) Iron (iii) Aluminium (iv) Carbon (v) Copper (vi) Mercury |
(a) Thermometers (b) Electric Wire (c) Wrapping food (d) Jewellery (e) Machinary (d) Fuel |
Mark ‘T’ if the statement is true and ‘F’ if it is false.
(a) Generally non-metals react with acids. ( )
(b) Sodium is a very reactive metal. ( )
(c) Copper displaces zinc from zinc sulphate solution. ( )
(d) Coal can be drawn into wires. ( )
Give reasons for the following:
(a) Aluminium foils are used to wrap food items.
(b) Immersion rods heating liquids are made up of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
(d) Sodium and potassium are stored in kerosene.
Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas ?
(b) Write down word equations of all the reactions taking place in this process.
What happens when
(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.
One day Reeta went to a jeweller’s shop with her mother. Her mother gave old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
Some properties are listed in the following Table. Distinguish between metals and non-metals on the basis of these properties.
Properties | Metals | Non-Metals |
---|---|---|
1. Appearance |
Fill in the blanks
(a) Most liquids that conduct electricity are solutions of , ______________ and ______________.
(b) The passage of an electric current through a solution causes ______________ effects.
(c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the terminal of the battery.
(d) The process of depositing a layer ofany desired metal on another material by means of electricity is called .
Give two examples each of situations in which you push or pull to change the state of motion of objects.
Fill in the blanks:
(a) Friction opposes the _____________ between the surfaces in contact with each other.
(b) Friction depends on the _____________ of surfaces. (c) Friction produces __________.
(d) Sprinkling of powder on the carrom board ________ friction.
(e) Sliding friction is ___________ than the static friction.
List conditions under which combustion can take place.
Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)
Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.
Fill in the blanks:
(a) A place where animals are protected in their natural habitat is called .
(b) Species found only in a particular area is known as .
(c) Migratory birds fly to far away places because of changes.
Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.
What are the different ways in which water gets contaminated ?
Explain the importance of reproduction in organisms.
Explain why objects moving in fluids must have special shapes.
Explain how soil gets affected by the continuous plantation of crops in a field.
Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.
(a) Polished wooden table (b) Chalk powder
(c) Cardboard surface (d) Marble floor with water spread over it
(e) Mirror (f) Piece of paper
Explain why a charged body loses its charge if we touch it with our hand.
Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)
Prepare a list of objects around you that are electroplated.
Name the forces acting on a plastic bucket containing water held above ground level in your hand. Discuss why the forces acting on the bucket do not bring a change in its state of motion.
Complete the word puzzle:
Down
1. Species on the verge of extinction.
2. A book carrying information about endangered species.
5. Consequence of deforestation.
Across
1. Species which have vanished.
3. Species found only in a particular habitat.
4. Variety of plants, animals and microorganisms found in an area.
Mark the following statements as true (T) or false (F):
(a) Pole Star is a member of the solar system. ( )
(b) Mercury is the smallest planet of the solar system. ( )
(c) Uranus is the farthest planet in the solar system. ( )
(d) INSAT is an artificial satellite. ( )
(e) There are nine planets in the solar system. ( )
(f) Constellation Orion can be seen only with a telescope. ( )
How are test tube babies born?