Electronic Configuration and Atomic Structure
The distribution of electrons in the various shells of atom is known as the electron configuration. There are different ways to write electronic configuration. This note explains what is electronic configuration and how to write it.
Summary
The distribution of electrons in the various shells of atom is known as the electron configuration. There are different ways to write electronic configuration. This note explains what is electronic configuration and how to write it.
Things to Remember
- The distribution of electrons in the various shells of atom is known as the electron configuration.
- Draw a small circle. Write 1P and 0 N. This represent nucleus.
- Draw another circle outside the inner circle. Since, the atom of hydrogen element contain 1 proton, the number of electron will be the same. Therefore, write e or Q the outer circle. This cell is k shell.
- Likewise there are higher shells such as L, M, N which hold different number of electrons.
MCQs
No MCQs found.
Subjective Questions
No subjective questions found.
Videos
No videos found.
Electronic Configuration and Atomic Structure
Electric configuration
The distribution of electrons in the various shells of an atom is known as the electron configuration. The following table shows the electronic configuration of some atoms.
Table 2: Electric configuration of atoms of some elements
| Elements | Symbol | Atomic number | Energy shells and number of electrons in them | |||
| K(1) | L(2) | M(3) | N(4) | |||
| Hydrogen | H | 1 | 1 | |||
| Helium | He | 2 | 2 | |||
| Lithium | Li | 3 | 2 | 1 | ||
| Beryllium | Be | 4 | 2 | 2 | ||
| Boron | B | 5 | 2 | 3 | ||
| Carbon | C | 6 | 2 | 4 | ||
| Nitrogen | N | 7 | 2 | 5 | ||
| Oxygen | O | 8 | 2 | 6 | ||
| Fluorine | F | 9 | 2 | 7 | ||
| Neon | Ne | 10 | 2 | 8 | ||
| Sodium | Na | 11 | 2 | 8 | 1 | |
| Magnesium | Mg | 12 | 2 | 8 | 2 | |
| Aluminum | Al | 13 | 2 | 8 | 3 | |
| Silicon | Si | 14 | 2 | 8 | 4 | |
| Phosphorous | P | 15 | 2 | 8 | 5 | |
| Sulfur | S | 16 | 2 | 8 | 6 | |
| Chlorine | Cl | 17 | 2 | 8 | 7 | |
| Argon | A r | 18 | 2 | 8 | 8 | |
| Potassium | K | 19 | 2 | 8 | 8 | 1 |
| Calcium | Ca | 20 | 2 | 8 | 8 | 2 |
How to draw the atomic structure of an atom?
To draw the atomic structure of hydrogen atom:
- Draw a small circle. Write 1P and 0 N. This represent nucleus.
- Draw another circle outside the inner circle. Since, the atom of hydrogen element contains 1 proton, the number of an electron will be the same. Therefore, write e or Q the outer circle. This cell is k shell.
The atomic structure of some or the element are shown as follow:
Hydrogen
The atomic number of hydrogen is 1 and its mass number is also 1.
Number of electrons = Atomic number = 1
Number of protons = Atomic number = 1
Number of neutrons = Mass number - Atomic number
Thus, the hydrogen atom contains only one proton in its nucleus at high speed in the lowest energy level.
| shell | K | L | M | N |
| no. of electrons | 1 | 0 | 0 | 0 |
Helium
Mass no. = 4
Atomic Number = 2
Proton = 2
Neutron = 2
Electron = 2
The atomic number of helium is 2 and its mass number is 4. Therefore, it contains 2 electrons, 2 protons, and 2 neutrons.
| shell | K | L | M | N |
| no. of electrons | 2 | 0 | 0 | 0 |
Lithium
Mass no. = 7
Atomic no. = 3
Proton = 3
Neutron = 4
Electrons = 3
| shell | K | L | M | N |
| no. of electrons | 2 | 1 | 0 | 0 |
Beryllium
Mass no. = 9
Atomic no. = 4
Proton = 4
Neutron = 5
Electron = 2, 2
| shell | K | L | M | N |
| no. of electrons | 2 | 2 | 0 | 0 |
Boron
Mass no. = 11
Atomic no. = 5
Proton = 5
Neutron = 6
Electron = 2, 3
| shell | K | L | M | N |
| no. of electrons | 2 | 3 | 0 | 0 |
Carbon
Mass no. = 12
Atomic no = 6
Proton = 6
Neutron = 6
Electron = 2, 4
The atomic weight of carbon is 6 and its mass is 12. Therefore, it contains 6 electrons, 6 protons, and 6 neutrons.
| shell | K | L | M | N |
| no. of electrons | 2 | 4 | 0 | 0 |
Lesson
Matter
Subject
Science
Grade
Grade 8
Recent Notes
No recent notes.
Related Notes
No related notes.