Question

Neon (atomic mass 10) and argon (atomic mass 18) are inert elements, which means that they very rarely form chemicalbonds. Give the electron configuration of their atoms and explain why these elements are inert.

Short answer

Neon has an electron configuration of 1s²2s²2p⁶, while Argon's is 1s²2s²2p⁶3s²3p⁶. These configurations indicate that the outer electron shells for both atoms are full (Neon's 2nd shell and Argon's 3rd shell), meaning they are chemically stable and hence, inert. They do not readily form chemical bonds with other atoms because they don't have tendencies to lose, gain, or share electrons.

Step-by-step solution

Electron Configuration of Neon

Neon (Ne) has an atomic number of 10, meaning that a neutral neon atom consists of 10 protons and 10 electrons. The electron configuration of Neon is 1s²2s²2p⁶.

Electron Configuration of Argon

Argon (Ar) has an atomic number of 18, implying that a neutral argon atom contains 18 protons and 18 electrons. The electron configuration of Argon is 1s²2s²2p⁶3s²3p⁶.

Explanation of Neon and Argon's Inertness

An atom is inert or chemically stable when its outermost electron shell is full, usually containing eight valence electrons (\(except 1s2\) which can only hold two). In the case of the neon and argon, their outer electron shell (2nd shell for Ne and 3rd shell for Ar) are full. Therefore these elements do not have a tendency to lose, gain, or share electrons and as such, do not readily form chemical bonds with other elements. This leads to their inertness.

Key concepts

Electron Configuration

Understanding the electron configuration of an element reveals the distribution of electrons among the energy levels, or shells, around the nucleus. This is crucial for predicting an atom's chemical behavior. A common analogy for electron configuration is to consider it a hotel's booking chart, where each electron is a guest in a specific room (orbital). For instance, neon's electron configuration, written as 1s²2s²2p⁶, shows that its first shell (1s) is fully occupied by two electrons, and its second shell is filled with eight electrons (2s and 2p orbitals). Similarly, argon's configuration, 1s²2s²2p⁶3s²3p⁶, indicates that its third shell also has eight electrons along with a full inner second shell.

These precise arrangements of electrons explain an element's behavior during chemical reactions. If you imagine electrons are the currency used to create chemical bonds, then knowing the amount and distribution is akin to understanding a business's spending pattern – essential information for predicting future investments or interactions.

Chemical Stability

Chemical stability can be thought of as the reluctance of an atom to participate in chemical reactions. Think about it like a perfectly balanced seesaw that doesn't need any more riders to maintain its equilibrium. Atoms, much like a balanced seesaw, achieve maximum stability when their outermost shell of electrons is full. This state minimizes the energy of the atom, the same way adding or removing riders would disrupt the balance. The noble gases, of which neon and argon are a part, have this full outer shell naturally, making them the chemical equivalent of a stable, balanced seesaw - hence they are very unreactive or inert.

This stability means that they don't seek out additional electrons nor do they want to give any away, translating to a lack of incentive to form bonds under normal conditions. The noble gases might be seen as the 'loners' of the periodic table, content with their complete electron shells and not looking to mingle by forming chemical bonds.

Valence Electrons

Valence electrons are the electrons in an atom's outermost shell and are crucial in dictating an atom's chemical properties and bonding behavior. These are like the hands of an atom that reach out to other atoms to form chemical bonds - be it handshakes, high-fives, or fist bumps (metaphorically speaking). In context, the elements neon and argon have full outer shells with eight valence electrons, which is considered a very stable arrangement.

Noble gases do not 'need' more 'hands' nor do they have 'spare hands' to form bonds, making them chemically unreactive. In everyday life, possessing a full wallet might discourage further earning or spending; similarly, having a complete set of valence electrons dissuades noble gases from engaging in chemical transactions. This gives them the reputation of being inert, as they don't actively participate in chemical reactions.