How many valence electrons does phosphorus(P) have?

The fifteenth element of the periodic table is phosphorus. The element of group-15 is phosphorus and its symbol is ‘P’. Phosphorus forms bonds through its valence electrons. This article discusses in detail the valence electrons of phosphorus(P). Hopefully, after reading this article you will know in detail about this.

How many electrons, protons and neutrons does phosphorus(P) have?

The nucleus is located in the center of the atom. Protons and neutrons are located in the nucleus. The atomic number of phosphorus(P) is 15. The atomic number is the number of protons. That is, the number of protons in the phosphorus is fifteen. Electrons equal to protons are located in a circular shell outside the nucleus. That is, the phosphorus atom has a total of fifteen electrons.

The number of neutrons in an element is obtained from the difference between the number of atomic masses and the number of atoms. That is, neutron number (n) = atomic mass number (A) – atomic number (Z)

We know that the atomic number of phosphorus is 15 and the atomic mass number is about 31(30.97376200u). Neutron (n) = 31 – 15 = 16. Therefore, the number of neutrons in phosphorus(P) is 16.

What are the valence electrons of phosphorus(P)?

The second element in group-15 is phosphorus(P). The valence electron is the total number of electrons in the last orbit. The total number of electrons in the last shell after the electron configuration of phosphorus is called the valence electrons of phosphorus(P). The valence electrons determine the properties of the element and participate in the formation of bonds. The fifteenth element in the periodic table is phosphorus(P).

How do you calculate the number of valence electrons in a phosphorus(P) atom?

The valence electrons has to be determined by following a few steps. The electron configuration is one of them. It is not possible to determine the valence electron without electron configuration. Knowing the electron configuration in the right way, it is very easy to determine the valence electrons of all the elements. There is an article published on this site detailing the electron configuration, you can read it if you want. However, this article briefly discusses electron configuration.

However, valence electrons can be easily identified by arranging electrons according to the Bohr principle. Now we will learn how to determine the valence electron of phosphorus(P).

Step-1: Determining the total number of electrons in phosphorus(P)

1^st we need to know the total number of electrons in the phosphorus(P) atom. To know the number of electrons, you need to know the number of protons in phosphorus. And to know the number of protons, you need to know the atomic number of the phosphorus element.

To know the atomic number we need to take the help of a periodic table. It is necessary to know the atomic number of phosphorus(P) elements from the periodic table. The atomic number is the number of protons. And electrons equal to protons are located outside the nucleus. That is, we can finally say that there are electrons equal to the atomic number in the phosphorus atom. From the periodic table, we see that the atomic number of phosphorus is 15. That is, a phosphorus atom has a total of fifteen electrons.

Step-2: Need to do electron configuration of phosphorus(P)

Step-2 is very important. In this step, the electrons of phosphorus(P) have to be arranged. We know that the phosphorus atom has a total of fifteen electrons. The electron configuration of the phosphorus shows that there are two electrons in the K shell, eight in the L shell, and five in the M shell(orbit). That is, the first shell of phosphorus(P) has two electrons, the second shell has eight electrons and the 3rd shell has five electrons. The number of electrons per shell of phosphorus is 2, 8, 5. The electron configuration of phosphorus through the sub-orbit is 1s² 2s² 2p⁶ 3s² 3p³. There is an article on this site detailing the electron configuration of phosphorus(P), you can read it if you want.

Step-3: Determine the valence shell and calculate total electrons

The third step is to diagnose the valence shell(orbit). The last shell after the electron configuration is called the valence shell. The total number of electrons in a valence shell is called a valence electron. The electron configuration of phosphorus shows that the last shell of phosphorus has five electrons. Therefore, the valence electrons of phosphorus(P) are five.

What is the valency of phosphorus(P)?

The ability of one atom of an element to join another atom during the formation of a molecule is called valency(valence). The number of unpaired electrons in the last orbit of an element is the valency of that element. Ground state electron configuration of phosphorus is 1s² 2s² 2p⁶ 3s² 3p_x¹ 3p_y¹ 3p_z¹. Here, this electron configuration shows that three unpaired electrons exist in the last orbit of phosphorus. Therefore, the valency of the phosphorus atom is 3.

Valency is determined from the electron configuration of the element in the excited state. The electron configuration of phosphorus(P*) in excited state will be 1s² 2s² 2p⁶ 3s¹ 3p_x¹ 3p_y¹ 3p_z¹ 3d_xy¹. This electron configuration shows that the last shell of the phosphorus atom has five unpaired electrons. So the valency of phosphorus is 5. The valency of phosphorus is determined depending on the bond formation.

How many valence electrons does phosphorus ion(P^3-) have?

The elements that have 5, 6, or seven electrons in the last shell receive the electrons in the last shell during bond formation. The elements that receive electrons and form bonds are called anions. That is, phosphorus(P) is an anion element. During the formation of a bond, the last shell of phosphorus receives three electrons and turns them into phosphorus ion(P^3-).

P + 3e^– → P^3-

The electron configuration of phosphorus ion(P^3-) is 1s² 2s² 2p⁶ 3s² 3p⁶. The electron configuration of phosphorus ion shows that phosphorus ion has three shells and the 3rd shell has eight electrons. This electron configuration shows that the phosphorus ion has acquired the electron configuration of argon. That is, in this case, the valence of phosphorus ions(P^3-) is -3. Since the last shell of a phosphorus ion has eight electrons, the valence electrons of phosphorus ion(P^3-) are eight.

Compound formation of phosphorus(P)

Phosphorus(P) participates in the formation of bonds through its valence electrons. This valence electron participates in the formation of bonds with atoms of other elements. Phosphorus atoms form bonds by sharing electrons with chlorine atoms. The electron configuration of chlorine shows that the valence electrons of chlorine are seven. Three chlorine atoms and one phosphorus atom make phosphorus trichloride(PCl₃) compounds by sharing electrons.

P + Cl₂ → PCl₃

As a result, the phosphorus(P) atom completes its octave and acquires the electron configuration of argon. On the other hand, chlorine also acquires the electron configuration of argon.

P₄ + 6 Cl₂ → 4 PCl₃ (balanced)

Therefore, one phosphorus atom shares electrons with three chlorine atoms to form the phosphorus trichloride(PCl₃) compound through a covalent bond. Phosphorus trichloride(PCl₃) is covalent bonding.