Explain Bohr-Bury scheme.

The Bohr-Bury scheme is a method used to determine the electron configuration of atoms. It helps visualize how electrons are arranged in different energy levels around the nucleus.

Key Features of the Bohr-Bury Scheme

• Energy Levels: Electrons occupy specific energy levels or shells, which are designated by numbers (1, 2, 3, etc.).
• Electron Capacity: Each shell can hold a maximum number of electrons, calculated using the formula 2n², where n is the shell number.
• Filling Order: Electrons fill the lowest energy levels first before moving to higher levels, following the order of increasing energy.

Electron Distribution

In the Bohr-Bury scheme, the distribution of electrons in the first few shells is as follows:

• First shell (n=1): Holds up to 2 electrons.
• Second shell (n=2): Holds up to 8 electrons.
• Third shell (n=3): Holds up to 18 electrons.
• Fourth shell (n=4): Holds up to 32 electrons.

Example: Neon Atom

For instance, the neon atom has 10 electrons. According to the Bohr-Bury scheme, its electron configuration would be:

• 2 electrons in the first shell
• 8 electrons in the second shell

This arrangement gives neon its stable, inert properties, as it has a full outer shell.

Importance in Chemistry

The Bohr-Bury scheme is crucial for understanding chemical bonding and reactivity. By knowing how electrons are arranged, one can predict how an atom will interact with others, forming compounds and molecules.