name the element in correct order of their increasing atom atomic numbers present in the first second and third short period of the periodic table state each element electronic configuration

Asked by addysahu7 | 31st May, 2019, 04:18: PM

Expert Answer:

First period contains 2 elements (Hydrogen and Helium) which has atomic numbers 1 and 2 respectively.
Second period contains 8 elements (Li, Be, B, C, N, O, F, Ne) which as atomic numbers 3, 4, 5, 6, 7 and 8 respectively.
Third period contain 8 elements (Na, Mg, Al, Si, P, S, Cl, Ar) which has atmoic numbers 9, 10, 11, 12, 13, 14, 15 and respectively.
 

Name

Atomic Number

Electron Configuration

Period 1

Hydrogen

1

1s1

Helium

2

1s2

Period 2

Lithium

3

1s2 2s1

Beryllium

4

1s2 2s2

Boron

5

1s2 2s22p1

Carbon

6

1s2 2s22p2

Nitrogen

7

1s2 2s22p3

Oxygen

8

1s2 2s22p4

Fluorine

9

1s2 2s22p5

Neon

10

1s2 2s22p6

Period 3

Sodium

11

1s2 2s22p63s1

Magnesium

12

1s2 2s22p63s2

Aluminum

13

1s2 2s22p63s23p1

Silicon

14

1s2 2s22p63s23p2

Phosphorus

15

1s2 2s22p63s23p3

Sulfur

16

1s2 2s22p63s23p4

Chlorine

17

1s2 2s22p63s23p5

Argon

18

1s2 2s22p63s23p6

 

Answered by Sivanand Patnaik | 2nd Jun, 2019, 08:04: PM