Chemistry Class Test-Class 9

Chemistry Class Test

Class-9

F.M=25

F.T=1Hr

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]