8th Std Science Lesson Wise Questions in English – Part 1

8th Science Lesson 4 Questions in English

4] Matter

1. Which of the following statement is incorrect?

1. The various objects which exist around us are made of some kind of matter.
2. In the universe all manifestations, phenomena and evolution of life are caused by matter and energy
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

In the universe all manifestations, phenomena and evolution of life are caused by matter and energy. The various objects which exist around us are made of some kind of matter.

2. Match the following with their respective:

1. Glass tumbler 1. Felt
2. Agarbatti 2. Seen
3. Wind blowing 3. Smell
4. 1, 3, 2
5. 2, 1, 3
6. 2, 3, 1
7. 3, 2, 1

Explanation

We perceive some of these objects through our senses like sight, touch, hearing, taste and smelling. A glass tumbler can be seen, agarbatti burning can be recognized by its smell whereas wind blowing can be felt.

3. Assertion(A): Matter can be defined as anything, which occupies space or volume and mass and be perceived by our senses

Reason(R): All kinds of matter possess mass and occupy space, of course some are heavy and others are light

1. Both (A) and (R) are correct, but (R) does not explain (A)
2. Both (A) and (R) are wrong
3. Both (A) and (R) are correct and (R) explains (A)
4. (A) is Correct and (R) is wrong

Explanation

All kinds of matter possess mass and occupy space, of course some are heavy and others are light. Thus, matter can be defined as anything, which occupies space or volume and mass and can be perceived by our senses.

4. Match the following:

1. Solids 1. Oxygen
2. Liquids 2. Iron
3. Gases 3. Fruit juice
4. 2, 1, 3
5. 2, 3, 1
6. 3, 1, 2
7. 1, 3, 2

Explanation

As we know already matter exists in:

• Solids: Substances like wood, stone, sand, iron etc.
• Liquids: Substances like water, milk, fruit juice, etc
• Gases: Substances like oxygen, nitrogen, carbon dioxide, steam, etc.,

5. By which of the following a matter is composed of?

1. Atom
2. Molecule
3. Ions
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Matter in any physical state is composed of smaller particles such as atom, molecules or ions. Molecules are also made up of atoms of same or different kinds. Hence, atoms are the building blocks of matter.

6. Which of the following statement about atom is correct?

1. An atom is the smallest particle of an element, which exhibits all the properties of that element.
2. It may or may not exist independently but takes part in every chemical reaction
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

An atom is the smallest particle of an element, which exhibits all the properties of that element. It may or may not exist independently but takes part in every chemical reaction.

7. _____is the smallest particle of a pure substance

1. Atom
2. Molecule
3. Electron
4. Ion

Explanation

Atoms of the same element or different elements combine to form a molecule. A molecule is the smallest particle of a pure substance (element or compound), which can exist independently and retain the physical and chemical properties of the substance.

8. Who used symbols to represent the four basic elements around us?

1. Aryans
2. Romans
3. Dravidians
4. Greeks

Explanation

The symbols in form of the geometrical shapes were those used by the ancient Greeks to represent the four basic elements around us such as earth, air, fire and water.

9. Which of the following statement is correct?

1. In the days of alchemists, the different materials that they used were represented by the above-mentioned symbols while they try to change less valuable metal into gol
2. The process was called alchemy and the men who did this work were known as alchemists
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

In the days of alchemists, the different materials that they used were represented by the above-mentioned symbols while they try to change less valuable metal into gold. The process was called alchemy and the men who did this work were known as alchemists.

10. Which English scientist tried to name the various elements based on these pictorial symbols?

1. Dalton
2. Edison
3. Einstein
4. Darwin

Explanation

In 1808, John Dalton, English scientist tried to name the various elements based on these pictorial symbols. These symbols are difficult to draw and hence they are not used. It is only of historical importance.

11. Match the following:

1. 1. Nickel
2. 2. Antimony
3. 3. Water
4. 4. Arsenic
5. 2, 1, 3, 4
6. 1, 3, 2, 4
7. 1, 4, 2, 3
8. 1, 2, 3, 4

Explanation

12. Match the following:

1. 1. Carbon
2. 2. Copper
3. 3. Alumina
4. 4. Nitrogen
5. 3, 1, 2, 4
6. 1, 2, 4, 3
7. 2, 1, 4, 3
8. 1, 3, 2, 4

Explanation

13. Who devised a system using letters of alphabet rather than signs?

1. Dalton
2. Einstein
3. Jon Jakob Mendeleev
4. Jacob

Explanation

In 1813, Jon Jakob Berzelius devised a system using letters of alphabet rather than signs.,. The modified version of Berzelius system follows under the heading ‘System for Determining Symbols of the Elements’.

14. What does the symbol B represent?

1. Beryllium
2. Boron
3. Bismuth
4. Barium

Explanation

15. What does the term Ba represent?

1. Boron
2. Barium
3. Beryllium
4. Bromine

Explanation

16. What does the symbol As represent?

1. Arsenic
2. Argon
3. Amalgam
4. Aluminium

Explanation

17. Which of the following metal’s symbol does not come from its Latin name?

1. Silver
2. Tin
3. Argon
4. Antimony

Explanation

18. Which of the following metal is named after Alfred Nobel?

1. Americium
2. Nobelium
3. Neptunium
4. Iodine

Explanation

19. Which of the following planet name is not used to name an element?

1. Pluto
2. Neptune
3. Uranium
4. Mars

Explanation

20. What does the symbol O represent?

1. Oxygen molecule
2. One atom of Oxygen
3. Molecule of Carbon monoxide
4. Atom of carbon

Explanation

Symbol of an element signifies:

• Name of the element
• One atom of the element
• For example, the symbol O stands for the element of Oxygen, One atom of oxygen

21. Which of the following statement is correct?

1. The progress of man towards civilization is linked with the discovery of several metals and non-metals
2. Even today, the index of prosperity of a country depends upon the amount of metals and non-metals it produces and uses
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

The progress of man towards civilization is linked with the discovery of several metals and non-metals. Even today, the index of prosperity of a country depends upon the amount of metal and non-metals it produces and uses.

22. The wealth of a country is measured by the amount of____ in its reserve.

1. Gold
2. Silver
3. Iron
4. Mercury

Explanation

The wealth of a country is measured by the amount of gold in its reserve. These days, metals and non-metals are used for making tools, machines, cars, utensils, etc. Some of the common metals used are iron, copper, silver, gold, lead, zinc, aluminium, magnesium, nickel, chromium and mercury etc. Similarly, the common non-metals used are nitrogen, oxygen, hydrogen, carbon, sulphur, phosphorus and chlorine etc.

23. Which of the following statement is incorrect?

1. An element can be identified as metal or non-metal by comparing its properties with the general properties of metals and non- metals.
2. In doing so, we find that some elements neither fit with the metals or with non-metals, they are called as metalloid
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

An element can be identified as metal or non-metal by comparing its properties with the general properties of metals and non- metals. In doing so, we find that some elements neither fit with the metals or with non-metals. Such elements are called semi-metals or metalloids. Elements are classified into metals, non-metals, and metalloids based on their properties.

24. Which of the following metals become liquid at or just above room temperature?

1. Francium
2. Mercury
3. Gallium
4. All the above

Explanation

Metals are solid under normal conditions of temperature and pressure. Mercury is liquid at room temperature. Elements Caesium (Cs), rubidium (Rb), Francium (Fr) and Gallium (Ga) become liquid at or just above room temperature

25. _____is so hard that it can scratch glass

1. Sodium
2. Diamond
3. Osmium
4. Potassium

Explanation

Most metals are hard. The exception here is sodium and potassium, which is soft enough to be cut by a knife. Osmium is so hard that it can scratch glass.

26. Which of the following metal does not Lustre?

1. Iron
2. Gold
3. Calcium
4. Silver

Explanation

All metals are shiny. Th e typical shine of metals is called metallic lustre. All metals have a typical metallic lustre. An exception is calcium.

27. Which of the following metal have low density?

1. Sodium
2. Zinc
3. Potassium
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Metals generally have high density. Sodium and potassium have exceptionally low density. All metals have a typical metallic lustre.

28. Which metal does not have high melting point and boiling point?

1. Sodium
2. Potassium
3. Mercury
4. Gallium
5. 1, 2, 3
6. 2, 3, 4
7. 1, 3, 4
8. All the above

Explanation

Melting point and boiling point: Metals in general have high melting point and boiling point. Sodium, potassium, mercury and gallium are exceptions.

29. Which of the following statement is correct?

1. Metals have the capacity to withstand strain without breaking
2. It is the property that owes the use of iron for the construction of railway tracks
3. Zinc, arsenic and antimony are exceptions.
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Metals have the capacity to withstand strain without breaking. Th is property is called tensile strength. It is the property that owes the use of iron for the construction of railway tracks. Zinc, arsenic and antimony are exceptions

30. Which metal have the property to transform into silvery foils?

1. Gold
2. Silver
3. Aluminium
4. Zinc

Explanation

Metals can be hammered into very thin sheets. Th is tendency of metals is called malleability. Aluminium makes use of this property to transform into silvery foils.

31. Property of making metals into thin wire is called_________

1. Conductivity
2. Ductility
3. Lustre
4. Hardness

Explanation

Ductility: Metals can be drawn into thin wires. This property of metals is called ductility. Example: copper wires.

32. Which of the following metal is/are poor conductor of electricity?

1. Bismuth
2. Tungsten
3. Silver
4. Both a and b

Explanation

Metals are good conductors of heat and electricity. Silver and copper are very good conductors of electricity. However, bismuth and tungsten are poor conductors.

33. _____ property is being made used in making temple bells

1. Malleability
2. Sonorous
3. Ductility
4. Tensile strength

Explanation

On being hit, metals produce a typical sound. Hence, they are said to be sonorous. This property is being made used in making temple bells.

34. Which of the following are non-metals?

1. Sulphur
2. Carbon
3. Oxygen
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Elements that generally do not shine, neither too hard nor too soft, are non-metals. All gases are non-metals. Some non-metals are Sulphur, Carbon, Oxygen etc.

35. Which of the following non-metal occurs in solid state?

1. Sulphur
2. Phosphorus
3. Oxygen
4. Both a and b

Explanation

Non-metals occur as solids, liquids or gases at normal temperature, for example sulphur, phosphorus occurs in solid state while bromine occurs in liquid state. Gases like oxygen, nitrogen, etc., occur in the gaseous state.

36. Which of the following statement is correct?

1. Non-metals are generally not hard except diamond
2. Non-metals have a dull appearance; Graphite and iodine are exceptions as they are shiny and lustrous
3. 1 alone
4. 2 alone
5. 1, 2
6. None

Explanation

Non-metals are generally not hard except diamond (a form of carbon). Non-metals have a dull-appearance; Graphite and iodine are exceptions as they are shiny.

37. Which of the following non-metals have high melting and boiling point?

1. Carbon
2. Silicon
3. Boron
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Nonmetals have low melting point and boiling point. However, carbon, silicon and boron are exceptions. Non-metals do not have tensile strength. However, carbon fibre (a form of carbon) is as tensile as steel.

38. Which of the following metal properties are usually high?

1. Melting point
2. Boiling point
3. Density
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

39. ________ is used in electrical wires, cables and in aerospace industries

1. Silver
2. Aluminium
3. Bronze
4. Mercury

Explanation

Uses of Metals:

• Iron is used for making bridges, engine parts, iron-sheet and bars.
• Copper is used for making electrical wires, coins and statue.
• Silver and gold are used for making jewels, in decorative purposes and photography
• Mercury is used in thermometers and barometers because of its high density and uniform expansion at different temperature.
• Aluminium is used in electrical wires, cables and in aerospace industries.

40. _________ is used in making pencil lead.

1. Diamond
2. Graphite
3. Fullerance
4. None

Explanation

Diamond (a form of carbon) is used for making jewels, cutting and grinding equipment. Graphite is used in making pencil lead.

41. _______ is used in the manufacturing of gun powder

1. Zinc
2. Sulphur
3. Lead
4. Phosphorous

Explanation

Sulphur is used in the manufacturing of gun powder and vulcanization of rubber. Phosphorus is used in matches, rat poison etc.

42. _____ is used as a bleaching agent and in sterilizing water.

1. Sulphur
2. Chlorine
3. Hydrogen
4. Nitrogen

Explanation

Nitrogen is used for manufacturing ammonia. Chlorine is used as a bleaching agent and in sterilizing water. Hydrogen is used as a rocket fuel and hydrogen flame is used for cutting and welding purposes, as well as a reducing agent.

43. Which of the following is/are Metalloids?

1. Silicon
2. Arsenic
3. Antimony
4. All the above

Explanation

The elements which exhibit the properties of metals as well as non-metals are called metalloids. Examples: boron, silicon, arsenic, germanium, antimony, tellurium and polonium.

44. Which of the following are the Physical properties of metalloids?

1. They can form alloys with other metals
2. The physical properties of metalloids tend to be metallic, but their chemical properties tend to be non-metallic.
3. Silicon for example appears lustrous, but is not malleable nor ductile (it is brittle – a characteristic of some non-metals)
4. 1, 2
5. 1, 3
6. 2, 3
7. All the above

Explanation

Physical properties of metalloids:

Metalloids are all solid at room temperature

• They can form alloys with other metals
• Some metalloids, such as silicon and germanium, can act as electrical conductors under the specific conditions, thus they are called semiconductors.
• Silicon for example appears lustrous, but is not malleable nor ductile (it is brittle – a characteristic of some non-metals). It is a much poorer conductor of heat and electricity than the metals
• The physical properties of metalloids tend to be metallic, but their chemical properties tend to be non-metallic

45. What is the ratio of mass of water oxygen and hydrogen atoms?

1. 8:1
2. 1:8
3. 1:2
4. 2:1

Explanation

Water, carbon di oxide, sodium chloride etc. are few examples of compounds. A molecule of water is composed of an oxygen atom and two hydrogen atoms in the ratio 1:2 by volume or 8:1 by mass.

46. Which of the are the Constitutent Elements of Zinc carbonate?

1. Zinc
2. Carbon
3. Sulphur
4. Oxygen
5. 1, 2, 4
6. 2, 3, 4
7. 1, 2, 3
8. All the above

Explanation

47. What is the Consititutent Elements of Vinegar?

1. Hydrogen
2. Carbon
3. Oxygen
4. Sulphur
5. 1, 2, 3
6. 1, 2, 4
7. 2, 3, 4
8. All the above

Explanation

48. Match the following:

1. Baking soda 1. Calcium hydroxide
2. Quick lime 2. Sodium bicarbonate
3. Slaked lime 3. Calcium oxide
4. Bleaching powder 4. Calcium hydroxide
5. 2, 1, 3, 4
6. 2, 3, 4, 1
7. 3, 1, 2, 4
8. 1, 2, 3, 4

Explanation

49. Match the following:

1. Copper sulphate 1. Blue Vitriol
2. Calcium sulphate 2. Gypsum
3. Potassium chloride 3. Muriate of potash
4. Sulphuric acid 4. Oil of Vitriol
5. 1, 3, 2, 4
6. 1, 2, 3, 4
7. 1, 3, 4, 2
8. 2, 1, 4, 3

Explanation