Atoms and Molecules English Medium Free Online Test 1 Mark Questions 2020-2021

10th Standard

    Reg.No. :
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Science

Time : 00:15:00 Hrs
Total Marks : 15

    Part A

    15 x 1 = 15
  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 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

  3. 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

  4. Pick out the isotopes among the following pairs

    (a)

    6C13, 7N14

    (b)

    18Ar4, 20Ca4

    (c)

    6C12, C614

    (d)

    5B12, 6C13

  5. Mass number is the

    (a)

    Number of protons

    (b)

    Sum of protons and electrons

    (c)

    Number of neutrons

    (d)

    Sum of protons and neutrons

  6. 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

  7. The relative atomic masses of many elements are not whole number because

    (a)

    they are not determined accurately

    (b)

    they exist as isotopes

    (c)

    due to impurities

    (d)

    atoms ionize

  8. Total number of atoms in 4g of oxygen molecule is

    (a)

    6.023 x 1023

    (b)

    7.52 x 1022

    (c)

    1.5055 X 1023

    (d)

    0.0752 x 1023

  9. What mass of hydrogen and oxygen will be produced on complete electrolysis of 18 g of water

    (a)

    2 g hydrogen and 32 g oxygen

    (b)

    2 g hydrogen and 16 g oxygen

    (c)

    4 g hydrogen and 32 g oxygen

    (d)

    4 g hydrogen and 14 g oxygen

  10. Which of the following has largest number of particles?

    (a)

    8g of CH4

    (b)

    4.4g of CO2

    (c)

    34.2g of C12H22P11

    (d)

    2 g of H2

  11. The formula of a chloride of a metal M is MCl3 the formula of the phosphate of metal Mwill be:

    (a)

    MPO4

    (b)

    M2PO4

    (c)

    M3PO4

    (d)

    2 (PO4)3

  12. The mass of one C atom is

    (a)

    6.023 x 1023g

    (b)

    1.99 x 10-23g

    (c)

    2.00 g

    (d)

    12 g

  13. The total number of atoms represented by the compound CuSO4. 5H2O is

    (a)

    27

    (b)

    21

    (c)

    5

    (d)

    8

  14. How many molecules are present in one gram of hydrogen?

    (a)

    6.023 x 1023

    (b)

    3.0115 x 1023

    (c)

    2.5 X 1023

    (d)

    1.5 x 1023

  15. 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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