Electronic Configuration of Elements 1–30 with Table & MCQs

Learning the electronic configuration of elements is the key to understanding how atoms behave, bond, and form compounds. From simple elements like Hydrogen to transition metals like Zinc, each has a unique pattern that explains its properties. The table below shows the electronic configuration, shell distribution, and valency of the first 30 elements in the periodic table. Following the table, we offer MCQs to help you quickly revise and test your knowledge in a fun and effective way.

Electronic Configuration of Elements (1–30)

Atomic Number	Element (Symbol)	Electronic Configuration (Subshell wise)	Electronic Configuration (Shell wise)	Valency
1	Hydrogen (H)	1s¹	1	1
2	Helium (He)	1s²	2	0
3	Lithium (Li)	1s² 2s¹	2, 1	1
4	Beryllium (Be)	1s² 2s²	2, 2	2
5	Boron (B)	1s² 2s² 2p¹	2, 3	3
6	Carbon (C)	1s² 2s² 2p²	2, 4	4
7	Nitrogen (N)	1s² 2s² 2p³	2, 5	3
8	Oxygen (O)	1s² 2s² 2p⁴	2, 6	2
9	Fluorine (F)	1s² 2s² 2p⁵	2, 7	1
10	Neon (Ne)	1s² 2s² 2p⁶	2, 8	0
11	Sodium (Na)	1s² 2s² 2p⁶ 3s¹	2, 8, 1	1
12	Magnesium (Mg)	1s² 2s² 2p⁶ 3s²	2, 8, 2	2
13	Aluminium (Al)	1s² 2s² 2p⁶ 3s² 3p¹	2, 8, 3	3
14	Silicon (Si)	1s² 2s² 2p⁶ 3s² 3p²	2, 8, 4	4
15	Phosphorus (P)	1s² 2s² 2p⁶ 3s² 3p³	2, 8, 5	3, 5
16	Sulphur (S)	1s² 2s² 2p⁶ 3s² 3p⁴	2, 8, 6	2
17	Chlorine (Cl)	1s² 2s² 2p⁶ 3s² 3p⁵	2, 8, 7	1
18	Argon (Ar)	1s² 2s² 2p⁶ 3s² 3p⁶	2, 8, 8	0
19	Potassium (K)	1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹	2, 8, 8, 1	1
20	Calcium (Ca)	1s² 2s² 2p⁶ 3s² 3p⁶ 4s²	2, 8, 8, 2	2
21	Scandium (Sc)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s²	2, 8, 9, 2	3
22	Titanium (Ti)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²	2, 8, 10, 2	4
23	Vanadium (V)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d³ 4s²	2, 8, 11, 2	5
24	Chromium (Cr)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹	2, 8, 13, 1	2
25	Manganese (Mn)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²	2, 8, 13, 2	2, 4, 7
26	Iron (Fe)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²	2, 8, 14, 2	2, 3
27	Cobalt (Co)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷ 4s²	2, 8, 15, 2	2, 3
28	Nickel (Ni)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁸ 4s²	2, 8, 16, 2	2
29	Copper (Cu)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹	2, 8, 18, 1	1, 2
30	Zinc (Zn)	1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²	2, 8, 18, 2	2

MCQ Questions for Electronic configuration of elements 1 to 30

Question 1. What is the electronic configuration of Hydrogen?

a) 1s²
b) 1s¹
c) 2s¹
d) 2p¹

Answer:

b) 1s¹ - Hydrogen has one electron in the 1s orbital.

Question 2. Which element has the electronic configuration 1s² 2s² 2p⁶?

a) Oxygen
b) Neon
c) Nitrogen
d) Fluorine

Answer:

b) Neon - Neon has 10 electrons with configuration 1s² 2s² 2p⁶.

Question 3. Sodium (Na) has how many electrons in its outermost shell?

a) 1
b) 2
c) 3
d) 8

Answer:

a) 1 - Sodium has configuration 2, 8, 1.

Question 4. Which element has the configuration 1s² 2s² 2p⁶ 3s² 3p³?

a) Phosphorus
b) Sulphur
c) Chlorine
d) Argon

Answer:

a) Phosphorus - Atomic number 15, with 5 electrons in the outermost shell.

Question 5. What is the valency of Magnesium (Mg)?

a) 1
b) 2
c) 3
d) 4

Answer:

b) 2 - Magnesium (2, 8, 2) loses 2 electrons to become stable.

Question 6. Which element has 2, 8, 8 electronic configuration?

a) Argon
b) Calcium
c) Sulphur
d) Potassium

Answer:

a) Argon - Atomic number 18, a noble gas with stable configuration.

Question 7. What is the subshell configuration of Carbon (
c)?

a) 1s² 2s² 2p¹
b) 1s² 2s² 2p²
c) 1s² 2s² 2p³
d) 1s² 2s¹

Answer:

b) 1s² 2s² 2p² - Carbon has 6 electrons.

Question 8. Which element has the valency of zero?

a) Fluorine
b) Helium
c) Lithium
d) Sodium

Answer:

b) Helium - Noble gases (full shells) have valency 0.

Question 9. What is the electronic configuration of Potassium (K)?

a) 2, 8, 8, 1
b) 2, 8, 7
c) 2, 8, 8, 2
d) 2, 8, 1

Answer:

a) 2, 8, 8, 1 - Potassium has 19 electrons.

Question 10. Which element has the configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²?

a) Scandium
b) Calcium
c) Titanium
d) Zinc

Answer:

b) Calcium - Atomic number 20.

Question 11. Which of the following is a transition element?

a) Sodium
b) Zinc
c) Neon
d) Magnesium

Answer:

b) Zinc - Transition metals include elements from Sc (21) to Zn (30).

Question 12. The configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹ belongs to?

a) Manganese
b) Chromium
c) Iron
d) Cobalt

Answer:

b) Chromium - Atomic number 24, shows exceptional stability (half-filled d-orbital).

Question 13. What is the shell-wise configuration of Aluminium (Al)?

a) 2, 8, 1
b) 2, 8, 2
c) 2, 8, 3
d) 2, 8, 4

Answer:

c) 2, 8, 3 - Aluminium has 13 electrons.

Question 14. Which element has a fully filled d-subshell (3d¹⁰)?

a) Copper
b) Nickel
c) Zinc
d) Iron

Answer:

c) Zinc - Atomic number 30, configuration ends with 3d¹⁰ 4s².

Question 15. Which element has 7 electrons in its outermost shell?

a) Oxygen
b) Nitrogen
c) Fluorine
d) Sodium

Answer:

c) Fluorine - Configuration 2, 7.

Question 16. What is the valency of Oxygen?

a) 1
b) 2
c) 3
d) 4

Answer:

b) 2 - Oxygen (2, 6) needs 2 electrons to complete octet.

Question 17. Which element has the configuration 2, 8, 14, 2?

a) Iron
b) Nickel
c) Cobalt
d) Zinc

Answer:

a) Iron - Atomic number 26.

Question 18. Which element has the electronic configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹?

a) Nickel
b) Copper
c) Zinc
d) Scandium

Answer:

b) Copper - Atomic number 29, shows stability with full d-orbital.

Question 19. How many electrons are present in the third shell of Sulphur (S)?

a) 4
b) 5
c) 6
d) 16

Answer:

c) 6 - Sulphur’s configuration is 2, 8, 6.

Question 20. Which element has the configuration 1s² 2s² 2p⁶ 3s² 3p⁵?

a) Oxygen
b) Chlorine
c) Sulphur
d) Fluorine

Answer:

b) Chlorine - Atomic number 17, outer configuration 2, 8, 7.