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Friday, 1 December 2017

50 MCQ'S CLASS 9 PHYSICAL SCIENCE - ( IS MATTER PURE, ATOMS AND MOLECULES, WHAT'S INSIDE AN ATOM)



1. Which of the following provides an example of a true solution?

A)    Blood
B)    Milk
C)    Starch solution
D)    Sugar solution

2. Which of the following can be classified as a pure substance?

A)    Milk
B)    Sea - water
C)    Ice
D)    Cast iron

3. Which of the following is a compound?

A)    air
B)    Milk 
C)    Iodine
D)    Water

4. Which of the following is NOT true about colloids?

A)    Particles in a colloid can pass through filter paper.
B)    A colloid is a homogeneous solution.
C)    Colloidal particles exhibit Brownian motion.
D)    Colloidal particles exhibit electrophoresis
5. Which of the following is a heterogeneous mixture?

A)    Air
B)    brass
C)    sugar dissolved in water
D)    lime water

6. How can we separate cream from milk?

A)    Centrifugation
B)    Chromatography
C)    Sublimation
D)    Distillation

7. Removal of clear layer of the liquid without disturbing the settled solid is known as __________.

A)    Sedimentation
B)    Decantation
C)    Filtration
D)    Evaporation

8. A mixture of water and silver chloride can be separated by

A)    Centrifugation
B)    Sedimentation
C)    Filtration
D)    Sublimation

9. When two liquids in a mixture differ by their boiling points, which of the following is the best method to separate these liquids?

A)    Evaporation
B)    Distillation
C)    Chromatography
D)    Filtration

10. Solution which has uniform composition throughout is called ___________.

A)    homogeneous solution
B)    heterogeneous solution
C)    Colloidal solution
D)    none of these

11. The particles of a suspension will be of size ________

A)    less than 1nm (nm = nano metre)
B)    between 1nm to 100 nm
C)    greater than 100nm
D)    less than 0.1 nm

12. Which of the following is a chemical change?

A)    Melting of ice
B)    Dissolving salt in water
C)    Rusting of iron
D)    Boiling of water into steam

13.  Which one of the following is TRUE for compounds?
A)    It shows properties of its constituents.
B)    It may be homogeneous or heterogeneous.
C)    It can be separated by physical methods.
D)    It has fixed melting and boiling point.
14. In water, hydrogen and oxygen are present in the ratio of ________.

A)    1:8
B)    2:12
C)    2:3
D)    1:2

15. An example of a triatomic molecule is ___________.

A)    Ozone
B)    Nitrogen
C)    Carbon monoxide
D)    Hydrogen

16. The quantity of matter present in an object is called its _________.

A)    Mass
B)    Volume
C)    Density
D)    Vapour pressure

17. Indivisibility of an atom was proposed by ___________.

A)    Dalton
B)    Rutherford
C)    Thomson
D)    Bohr

18.The value of Avogadro constant is ___________.

A)    6.022 x 1024
B)    6.022 x 1022
C)    60.22 x 1023
D)    6.022 x 1023

19. All samples of carbon dioxide contain carbon and oxygen in the mass ratio of 3:8. This is in agreement with the Law of ___________.

A)    Conservation of Mass
B)    Constant Proportion
C)    Multiple Proportion
D)    Reciprocal Proportion

20. The atomic mass of sodium is 23. The number of moles in 46g of sodium is ________.

A)    2
B)    1
C)    4
D)    0

21. The molecular formula of potassium nitrate is ________.

A)    KNO
B)    KNO3
C)    KNO2
D)    KON

22.  Kalium is the Latin name of ________.

A)    Potassium
B)    Krypton
C)    Calcium
D)    Phosphorus


23.   The smallest particle of a substance that is capable of independent existence is _________.

A)    Atom
B)    Molecule
C)    Electron
D)    Proton

24.   The molecular mass of ammonia is _________.

A)    17 grams
B)    31 grams
C)    20 grams
D)    25 grams

25. Atomic mass of calcium is 40. The mass of 2.5 gram atoms of calcium is _______.

A)    40 g
B)    2.5 g
C)    100 g
D)    80 g

26.  The number of atoms in a molecule of the elementary substance is called ________.

A)    Atomic number
B)    Avogadro number
C)    Atomic mass
D)    Atomicity

27.  Avogadro number represents the number of atoms in ________.

A)    12 grams of 12C
B)    320 grams of sulphur
C)    32 grams of oxygen
D)    1 gram of 12C

28. The number of moles in 5 grams of calcium is _________.

A)    0.125 mole
B)    5 mole
C)    1.25 mole
D)    12.5 moles

29.   2 molecules of nitrogen are represented by ________.

A)    N
B)    2N2
C)    N2
D)    2N

30.  Select the ionic compound -

A)    Sulphur molecule, S8
B)    Phosphorous molecule, P4
C)    Methane, CH4
D)    Copper nitrate, Cu(NO3)2  

31. Which of the following does not change when a chemical reaction takes place?

A)    volume
B)    mass
C)    physical properties
D)    chemical properties

32. One atomic mass unit is equal to weight of -

A)    one atom of hydrogen
B)    1/16th of oxygen atom
C)    1/12th of natural carbon atom
D)    1/12th of C-12 isotope of carbon.   

33.  Which one of the following is not equal to gram molecular mass of hydrogen -

A)    2 gm
B)    6.022 x 1023 atoms of hydrogen
C)    6.022 x 1023 molecules of hydrogen
D)    1 mole of hydrogen

34.  Proton was discovered by:

A)    Rutherford
B)    Goldstein
C)    Chadwick
D)    J.J. Thomson



35.  Canal rays are _______________

A)    negative charged particles
B)    positive charged particles
C)    beam of neutrons
D)    gamma radiation

36.  α-particles are ___________

A)    negative charged particles
B)    positive charged particles
C)    beam of neutrons
D)    gamma radiation

37.   An α-particle is _____________

A)    a Hydrogen nucleus
B)    a Helium nucleus
C)    a proton
D)    an electron

38.  Rutherford's gold foil experiment showed that most of the α-particles passed through the gold foil without any deflection. It indicates that

A)    the nucleus is concentrated at the centre
B)    the nucleus carries positive charge
C)    there is lot of empty space in atom
D)    the nucleus carries the most of the mass

39.  Two elements X and Y have the same atomic mass but their atomic numbers are 20 and 21 respectively. X and Y are:

A)    isobars
B)    isotones
C)    isomers
D)    isotopes

40.  In an atom, the mass number of an atom is equal to the number of _________________.

A)    nucleons
B)    protons
C)    electrons
D)    neutrons

41.  Number of neutrons present in Hydrogen atom is _______.

A)    0
B)    1
C)    2
D)    3

42.  Protium, Deutrium and Tritium are isotopes of ____________.

A)    Rhodium
B)    Sodium
C)    Hydrogen
D)    Helium

43.  If Z represents the atomic number and A represents mass number, then the number of neutrons in an atom can be computed as

A)    A + Z
B)    A – Z
C)    Z – A
D)    Z

44.  The electronic configuration of an atom is 2,8,3. The number of valence electrons in the atom is

A)    13
B)    10
C)    3
D)    8

45.  The number of electrons in the outermost shell in the atom of an inert element is

A)    0
B)    1
C)    2
D)    8

46.  Which one of the following will have the maximum charge/mass ratio?

A)    electron
B)    proton
C)    neutron
D)    α-particle

47.  The maximum number of electrons that can be accommodated in M shell is:

A)    2
B)    8
C)    18
D)    32

48. What is an electron?

A)    A wave
B)    A particle
C)    Either of two, depending on how it is observed
D)    Neither of these

49.  The atomic number of an element is 11 and its mass number is 23. The correct order representing the number of electrons, protons and neutrons respectively in this atom is:

A)    11, 11, 12
B)    11, 12, 11
C)    12, 11, 11
D)    23, 11, 23

50. The maximum number of electrons that can be accommodated in third shell ( n = 3) is:

A)    2
B)    8
C)    18
10

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