Which atoms are stable or unreactive? How many valence electrons do they have? Why do noble gasses not react with other atoms?
Atoms with full outer electron shells are considered stable or unreactive. These atoms include the noble gases, which are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
Noble gases have a complete set of valence electrons, typically eight, except for helium, which has two valence electrons. The octet rule states that atoms are most stable when their outermost energy level is filled with eight electrons. Since noble gases already have a full outer electron shell, they do not readily gain, lose, or share electrons with other atoms, making them unreactive.
This stability arises from the arrangement of electrons in their orbitals. The outermost energy level in noble gases is completely filled, resulting in a stable electron configuration. This configuration provides a strong electrostatic force of attraction between the positively charged nucleus and the negatively charged electrons, making it energetically unfavorable for noble gases to react and form chemical bonds with other elements.
Atoms of noble gases, also known as Group 18 elements, are generally stable and unreactive. This is primarily because they have a complete outer electron shell, which consists of a maximum number of valence electrons.
Noble gases have a total of 8 valence electrons, with the exception of helium which has only 2. The valence electrons are the electrons present in the outermost shell of an atom, and they determine an atom's chemical properties and reactivity.
The reason noble gases do not easily react with other atoms is due to their full outer electron shell. This complete shell configuration makes them highly stable, as it follows the octet rule, which states that atoms tend to gain, lose, or share electrons in order to achieve a full outer shell with 8 electrons. Noble gases already possess this stable configuration, so they have no strong tendency to participate in chemical reactions with other elements.
Atoms that are stable or unreactive are known as noble gases. These include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
The stability of noble gases is due to their electron configuration. All noble gases have a full outer electron shell, which means they have achieved an electron configuration known as the octet rule. This makes them highly stable and unreactive.
To understand why noble gases have a full outer electron shell, we need to consider the concept of valence electrons. Valence electrons are the electrons in the outermost energy level (also known as the valence shell) of an atom. They are responsible for the atom's chemical reactivity.
Helium (He) has two valence electrons, while neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) each have eight valence electrons. This configuration satisfies the octet rule, which states that atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight valence electrons, similar to the nearest noble gas.
Noble gases do not react easily with other atoms because they have a stable configuration of eight valence electrons. This means they do not need to gain, lose, or share electrons with other atoms to achieve a stable state. Therefore, noble gases have little to no tendency to form chemical bonds or engage in chemical reactions. Their stability arises from the fact that their outer electron shell is already completely filled, making them chemically inert or unreactive.
In summary, noble gases are stable and unreactive because they have a full outer electron shell, with helium having two valence electrons and the other noble gases having eight valence electrons. This makes them satisfy the octet rule and eliminates the need for them to form chemical bonds with other atoms.