Make the pairs. 'A' 'B' a. Neutrons i. six electrons b. p-orbital ii. - 1 . 6 × 10 - 19 c. Charge on electron iii. Ultraviolet region d. Lyman series iv. Chadwick

Neutron was discovered by Chadwick. He measured velocity of protons knocked out from paraffins by an unidentified radiation from beryllium. p -orbital can contain maximum of six electrons. It can be measured by 2 . ( 2 l + 1 ) where l is azimuthal quantum number. Charge on an electron is - 1 . 6 × 10 - 19 . Charge of proton is same but opposite in sign. Lyman series comes under ultraviolet region. Electrons jump from n =2, 3, 4..... to n =1. The region of radiation is ultraviolet. 'A' 'B' a. Neutrons i. Chadwick b. p-orbital ii. six electron c. Charge on electron iii. - 1 . 6 × 10 - 19 d. Lyman series iv. Ultraviolet region

Complete the following information about the isotopes in the chart given below: Substance Mass Number Numbers of Protons Neutrons Electrons Carbon- 14 Lead- 208 Chlorine- 35 Uranium- 238 Oxygen- 18 Radium- 223 (Hints :- Refer to Periodic Table if required)

The given information about the isotopes in the chart can be completed by the formula, Atomic mass = Number of proton + Number of neutron , as given below: Carbon- 14 : Mass number- 14 , number of protons- 6 , number of neutrons- 8 and number of electrons- 6 . Lead- 208 : Mass number: 208 , number of protons- 82 , number of neutrons- 126 and number of electrons- 82 . Chlorine- 35 : Mass number- 35 , number of protons- 17 , number of neutrons- 18 and number of electrons- 17 . Uranium- 238 : Mass number- 238 , number of protons- 92 , number of neutrons- 146 and number of electrons- 92 . Oxygen- 18 : Mass number- 18 , number of protons- 8 , number of neutrons- 10 and number of electrons- 8 . Radium- 223 : Mass number- 223 , number of protons- 88 , number of neutrons- 135 and number of electrons- 88 . Substance Mass Number Numbers of Protons Neutrons Electrons C 14 8 14 6 8 6 Pb 208 82 208 82 126 82 Cl 35 17 35 17 18 17 U 238 92 238 92 146 92 O 16 8 16 8 8 8 Ra 223 88 223 88 135 88

Match the followings. Element Number of Neutron. a. Ar 18 40 i. 7 b. C 6 14 ii. 21 c. K 19 40 iii. 8 d. N 7 14 iv. 22

Number of neutron in argon = 40 - 18 = 22 Number of electron= 18 , Number of neutron in carbon = 14 - 6 = 8 Number of electron= 6 , Number of neutron in potassium = 40 - 19 = 21 Number of electron= 19 , Number of neutron in nitrogen = 14 - 7 = 7 Number of electron= 7 Element Number of neutron a. Ar 18 40 i. 22 b. C 6 14 ii. 8 c. K 19 40 iii. 21 d. N 7 14 iv. 7

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Chemistry>Chapter 4 - Structure of Atom>Exercises>Q 1

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Earn 100

Principal Quantum number describes-

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Important Questions on Structure of Atom

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Chemistry>Chapter 4 - Structure of Atom>Exercises>Q 2

Make the pairs.

'A'		'B'
a.	Neutrons	i.	six electrons
b.	p-orbital	ii.	$- 1.6 \times 10^{- 19}$
c.	Charge on electron	iii.	Ultraviolet region
d.	Lyman series	iv.	Chadwick

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Chemistry>Chapter 4 - Structure of Atom>Exercises>Q 3

Complete the following information about the isotopes in the chart given below:

Substance	Mass Number	Numbers of
Substance	Mass Number	Protons	Neutrons	Electrons
Carbon- $14$
Lead- $208$
Chlorine- $35$
Uranium- $238$
Oxygen- $18$
Radium- $223$