Atoms and Molecules

10th Standard EM

    Reg.No. :
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Science

Time : 00:45:00 Hrs
Total Marks : 30
    30 x 1 = 30
  1. Which of the following has the smallest mass?

    (a)

    6.023 × 1023 atoms of He

    (b)

    1 atom of He

    (c)

    2 g of He

    (d)

    1 mole atoms of He

  2. Which of the following is a triatomic molecule?

    (a)

    Glucose

    (b)

    Helium

    (c)

    Carbon dioxide

    (d)

    Hydrogen

  3. Th e volume occupied by 4.4 g of CO2 at S.T.P

    (a)

    22.4 litre

    (b)

    2.24 litre

    (c)

    0.24 litre

    (d)

    0.1 litre

  4. Mass of 1 mole of Nitrogen atom is

    (a)

    28 amu

    (b)

    14 amu

    (c)

    28 g

    (d)

    14 g

  5. Which of the following represents 1 amu?

    (a)

    Mass of a C – 12 atom

    (b)

    Mass of a hydrogen atom

    (c)

    1/12th of the mass of a C – 12 atom

    (d)

    Mass of O – 16 atom

  6. Which of the following statement is incorrect?

    (a)

    One gram of C – 12 contains Avogadro’s number of atoms.

    (b)

    One mole of oxygen gas contains Avogadro’s number of molecules

    (c)

    One mole of hydrogen gas contains Avogadro’s number of atoms

    (d)

    One mole of electrons stands for 6.023 × 1023 electrons.

  7. The volume occupied by 1 mole of a diatomic gas at S.T.P is

    (a)

    11.2 litre

    (b)

    5.6 litre

    (c)

    22.4 litre

    (d)

    44.8 litre

  8. In the nucleus of 20Ca40, there are 

    (a)

    20 protons and 40 neutrons

    (b)

    20 protons and 20 neutrons

    (c)

    20 protons and 40 electrons

    (d)

    40 protons and 20 electrons

  9. The gram molecular mass of oxygen molecule is

    (a)

    16 g

    (b)

    18 g

    (c)

    32 g

    (d)

    17 g

  10. 1 mole of any substance contains __________ molecules

    (a)

    6.023 × 1023

    (b)

    6.023 × 1023

    (c)

    3.0115 × 1023

    (d)

    12.046 × 1023

  11. The mass of an atom is measured in ____________

    (a)

    kg

    (b)

    amu

    (c)

    g

    (d)

    Pm

  12. Atoms of different elements with different atomic numbers, but same mass number are known as _________

    (a)

    isobars

    (b)

    isotopes

    (c)

    isotones

    (d)

    isomers

  13. Pick out the isotopes among the following pairs

    (a)

    6C13, 7N14

    (b)

    18Ar4, 20Ca4

    (c)

    6C12, C614

    (d)

    5B12, 6C13

  14. Which among the following is a homo atomic molecule?

    (a)

    N2

    (b)

    NH3

    (c)

    HCl

    (d)

    N2O

  15. Mass number is the

    (a)

    Number of protons

    (b)

    Sum of protons and electrons

    (c)

    Number of neutrons

    (d)

    Sum of protons and neutrons

  16. Which of the following statement regarding an atom is always correct?

    (a)

    An atom has equal number of electrons and protons

    (b)

    An atom has equal number of electrons and neutrons

    (c)

    An atom has equal number of electrons, protons and neutrons

    (d)

    An atom has equal number of protons and neutrons

  17. Mass of an electron is

    (a)

    9.1083 x 10-31kg

    (b)

    9.1083 x 10-24kg

    (c)

    1.67262 x 10-27kg

    (d)

    1.67 x 10-24gm

  18. Which of the following pairs are isotopes?

    (a)

    Oxygen and ozone

    (b)

    Ice and water

    (c)

    NO and NO2

    (d)

    Hydrogen and deuterium

  19. The atomic number of an element is 12 and its mass number is 24. The number of electrons, protons and neutrons respectively will be

    (a)

    12, 12, 24

    (b)

    24,12,12

    (c)

    12,12,12

    (d)

    12, 24,12

  20. Which of the following has an equal number of neutrons and protons?

    (a)

    protium

    (b)

    deuterium

    (c)

    tritium

    (d)

    magnesium

  21. The smallest particle of an element which involve in a chemical reaction is

    (a)

    Atom

    (b)

    Molecule

    (c)

    Mole

    (d)

    Avogadro's molecule

  22. 17Cl3517Cl37 form the pair of

    (a)

    Isotope

    (b)

    Isonar

    (c)

    Isotone

    (d)

    Isomer

  23. Isotones have equal number of

    (a)

    Proton

    (b)

    Electron

    (c)

    Neutron

    (d)

    Atom

  24. Which of the contains maximum number of molecules

    (a)

    1 g of CO2

    (b)

    1g of N2

    (c)

    1 g of H2

    (d)

    1 g of CH4

  25. One mole of a gas occupies a volume of 22.4 l. This is derived from:

    (a)

    Berzelius's hypothesis

    (b)

    Gay- Lussac's law

    (c)

    Avogadro's law

    (d)

    Dalton's law

  26. A group of atoms chemically bonded together is a (an):

    (a)

    Molecule

    (b)

    Atom

    (c)

    Salt

    (d)

    Element

  27. Adding electrons to an atom will result in a (an):

    (a)

    Molecule

    (b)

    Anion

    (c)

    Cation

    (d)

    Salt

  28. The mass of a molecule of water is:

    (a)

    3 x 10-26kg

    (b)

    3 x 10-23kg

    (c)

    1.5 X 10-26kg

    (d)

    2.5 x 10-26kg

  29. Which of the following is a diatomic molecule?

    (a)

    CO

    (b)

    CO2

    (c)

    SO3

    (d)

    PO4

  30. Isotopes have

    (a)

    Same physical properties and different chemical properties

    (b)

    Same chemical properties and different physical properties

    (c)

    Same physical and chemical properties

    (d)

    Different physical and chemical properties

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