Question: Why Outermost Shell Cannot Have More Than 8 Electrons?

Why is the number of electrons in the outermost shell important?

The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms.

Most of the elements important in biology need eight electrons in their outermost shell in order to be stable, and this rule of thumb is known as the octet rule..

What is the 2 8 8 rule in chemistry?

There is a 2-8-8 rule for these elements. The first shell is filled with 2 electrons, the second is filled with 8 electrons, and the third is filled with 8. You can see that sodium (Na) and magnesium (Mg) have a couple of extra electrons. They, like all atoms, want to be happy.

Why are there 8 electrons in the outer shell?

The eight- electrons stability of an atom is stemmed from the stability of the noble gases or the elder name inert gases, which had long been known as unreactive or noble. … However, this rule is justified for elements of second row in the periodic table, which their outermost- shell capacity is 8 electrons.

Can there be more than 8 electrons in a shell?

Unlike atoms from periods one and two that only have the s and p orbitals (total of 8 valence electrons), atoms like phosphorus, sulfur, and chlorine can have more than 8 electrons because they are not restricted to the s and p orbitals and have a d orbital for additional electrons needed for bonding.

Why is the maximum number of valence electrons 8?

This is because of the quantum nature of the atoms, where electrons are organized in shells: the first (named the K shell) has 2 electrons, the second (L-shell) has 8, the third (M shell) has 18. Atoms combine into molecules by trying in most cases to have valence electrons entirely filling a shell.

Why is 3rd shell 8 or 18?

The third shell of an atom has 18 electrons only not 8 electrons. You might be confused because first the electrons of 4s are filled and then the 10 electrons of 3d shells are filled. They are filled because of the n-l rule. … So after filling the 3s and 3p subshell with 8 electrons, the next shell to fill is the 4s one.

Can an atom make 8 bonds?

For that same reason, six or seven bonds are possible, and Xenon can form 8 covalent bonds in the compound XeO4! Meallic elements can definiely have more than eight valence electrons, however they do not tend to form covalent bonds.

Why can Xenon have more than 8 valence electrons?

Xe does not follow the octet rule. It actually bonds. … Xenon having valence electrons in the 4th energy level, will also have access to the 4d sublevel, thus allowing for more than 8 electrons. XeF4 is d2sp3 hybridized and contains 2 lone pair and 4 bonding pairs of valence electrons around the Xenon.

Why are electrons so important?

Electrons are also important for the bonding of individual atoms together. With out this bonding force between atoms matter would not be able to interact in the many reactions and forms we see every day. This interaction between the outer electron layers of an atom is call atomic bonding. It can occur in two forms.

Which elements have a complete outer shell?

Helium (He), neon (Ne), and argon (Ar), as group 18 elements, have outer electron shells that are full or satisfy the octet rule. This makes them highly stable as single atoms. Because of their non-reactivity, they are called the inert gases or noble gases.

Why is a full outer shell stable?

The basis of the octet rule is that atoms ‘want’ a full outer shell of electrons, i.e. they are most stable with a full outer shell. … In this case, we mean the atom does not react easily with other atoms). An atom can get a full outer shell by losing or gaining electrons.

Why can sulfur have more than 8 electrons?

Its structure is Here the sulfur atom has six electron pairs in its valence shell. An atom like phosphorus or sulfur which has more than an octet is said to have expanded its valence shell. This can only occur when the valence shell has enough orbitals to accommodate the extra electrons. … An octet would be 3s23p6.

Which elements can have more than 8 electrons around them?

Sulfur, phosphorus, silicon, and chlorine are common examples of elements that form an expanded octet. Phosphorus pentachloride (PCl5) and sulfur hexafluoride (SF6) are examples of molecules that deviate from the octet rule by having more than 8 electrons around the central atom.

Can the third shell hold 8 or 18 electrons?

Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons.

Why are there 18 electrons in the third shell?

The 3rd subshell consists of an s orbital , a set of (3)p orbitals and a set of (5)d orbitals. Each orbital holds 2 electrons and you will indeed find that you can fir 18 electrons in. … This is because it is the maximum capacity of the 3rd shell and it doesn’t tell about the order in which the electrons are filled.

Can two electrons be in the same shell?

The state of a system is completely described by a complete set of quantum numbers. … The Pauli exclusion principle says that no two electrons can have the same set of quantum numbers; that is, no two electrons can be in the same state. This exclusion limits the number of electrons in atomic shells and subshells.

Why are shells named KLMN?

The names of the electron shells come from a fellow named Charles G. Barkla, a spectroscopist who studied the X-rays that are emitted by atoms when they are hit with high energy electrons. … This innermost shell is now called the K-shell, after the label used for the X-ray.

What is the highest occupied energy level?

What is it meant by the highest occupied energy level in an atom? The highest occupied energy level in an atom is the electron-containing main energy level with the highest number.