Question

a}.Explain Bohr and Bury rules for distribution of electrons into different shells . B}. Draw the electronic structure of element X with atomic number 17 and element Y with atomic number 16

Answer 1

A)
<>The maximum no. of electrons present in a shell is given by the formula 2n²
( n is shell number).

<>The maximum number of electrons that can be accommodated outermost orbit is 8.

(iii) Electrons are not accommodated in a given shell, unless the inner shells are filled.

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B )

The element X with atomic no: 17 is Chlorine.
No : of protons = 17
No  : of electrons = 17

Electronic Configuration = 2 , 8 , 7

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The element X with atomic no: 16 is Sulphur.

No : of protons = 16
No  : of electrons = 16

Electronic Configuration = 2 , 8 , 6

Answer 2

Explanation:

Explain Bohr Bury rules for Distribution of Electrons into Different Shells

Electron distribution

The distribution of electrons in different orbits or shells is governed by a scheme known as Bohr bury scheme.The arrangement of electrons in various energy levels of an atom is known as the electronic configuration of the atom. According to this scheme.

The electrons are arranged around the nucleus in different energy levels or energy shells. The electrons first occupy the shell with the lowest energy i.e., closest to the nucleus.

The first or the innermost energy shell (K or n = 1) can take only two electrons.

The second shell (L or n = 2) can contain upto 8 electrons.

From third shell (M or n = 3) onwards, the shells become bigger. The third shell can accommodate as many as 18 electrons. In general, the maximum number of electrons that can be present in any shell is 2n2 where n is the number of energy shell. Thus, the first orbit (n = 1, known as K shell) can contain 2 × 12 = 2 electrons, the second orbit (n = 2, known as L shell) can contain 2 × 22 = 8 electrons.

Maximum No. of electrons in different orbits

Orbit

Value of n Maximum no. of electrons in the orbit

K

1 2 × 12 = 2

L 2

2 × 22 = 8

M

3 2 × 32 = 18

N 4

2 × 42 = 32

The outermost shell of an atom cannot have more than 8 electrons and the shell next to the outermost shell cannot have more than 18 electrons.