Chemistry Class Test-Class 9

Class Test

Chemistry Class Test




  1. Provide two differences between isotopes and isobars.                                 [2]
  2. Identify the following among the following elements-                                   [3]

12A24, 15B31, 16C32, 12D26, 13E26

a) Isotones b) Isotopes c) Isobars

3. Identify the following among the following elements-12A24, 15B31, 16C32, 12D26, 13E26

a) Metals and Non-metals

b) Reducing and oxidizing agents

c) Element(s) which belong to the group of Alkaline earth metals.

d) Non-metal with valency-2

e) Metal with valency 3                            [5]

4. Draw the electron dot structure of the formation of-

a) MgCl2

b) AlN

c) CH4

d) NH3

e) N2                                                        [10]

[Atomic Numbers – Mg-12, Cl-17,Al-13, N-7, C-6,H-1]

5. An element A (with atomic number 6) forms a compound with B (with atomic number 17). Identify the –

a) Formula of the compound

b) Nature of the compound

c) Mention any two general property of the compound.                          [1 ½ ]

6. Explain why electrovalent compounds possess a high melting point?          [1/2 ]

7. An Element X with atomic number 8 forms compounds with hydrogen (H), Carbon(C), and Sodium (Na) separately.

a) Write the formula of the compounds formed.

b) State the nature of the compound (ionic or covalent).

  [Atomic number of H=1, C=6, Na=11]                     [3]

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