Chemistry -Unit 1

UNIT-7 Atoms and Molecules (Assignment Questions) Part -A

I. Choose the correct answer

1. Number of electrons, protons and neutrons present in 17Cl³⁵, 17Cl³⁷ is-------

a) 17e¯ , 17p+, 17n b) 18e¯ , 18p+, 17n

17e¯ , 20p+, 19n 17e¯ , 17p+, 19n

c) 17e¯ , 17p+, 18n d) 18e¯ , 17p+, 18n

20e¯ , 20p+, 17n 17e¯ , 17p+, 20n

2. Isobars are defined as---------

a) Elements show same atomic number with different mass number

b) Elements show same mass number with different atomic number

c) Elements show same valency

d) None of these

3. The Atomicity of Glucose molecule is .

a) 6 b) 12 c)24 d) 18

4. The mass of 5 moles of sodium is -------------

a) 46g b) 34g c) 105g d) 115g

5. Number of atoms present in 3 moles of iron is--------

a) 6.023 x 10²³ b) 18.069 x 10²³ c) 12.046 x 10²³ d) None

Part - B

II. Short Answer.

6. Define : Relative atomic mass

7.Give any two examples for heteroatomic molecules 8.Calculate the number of moles in 46 g of Sodium?

Part - C

III. Write In detail.

9.Give the salient features of “Modern Atomic Theory”.

Rajeshkumar