The 30th element in the periodic table is zinc. The element of group-12 is zinc and its symbol is ‘Zn’. Zinc is a d-block element. Therefore, the valence electrons of zinc are determined differently. This article discusses in detail the valence electrons of zinc. Hopefully, after reading this article you will know in detail about this.
How many electrons and protons does zinc have?
The nucleus is located in the center of the atom. Protons and neutrons are located in the nucleus. The atomic number of zinc is 30. The atomic number is the number of protons. That is, the number of protons in zinc is thirty. Electrons equal to protons are located in a circular shell outside the nucleus. That is, a zinc atom has a total of thirty electrons.
What are the valence electrons of zinc?
The valence electron is the total number of electrons in the last orbit(shell). The 1st element in group-12 is zinc and it is the d-block element. The elements in groups 3-12 are called transition elements. But in the case of transition elements, the valence electrons remain in the inner shell. This is because the electron configuration of the transition elements shows that the last electrons enter the d-orbital.
The electron configuration of zinc shows that the last shell of zinc has two electrons and its last electrons(3d10) have entered the d-orbital. Here, the d-orbital is filled with electrons and there are two electrons at the last energy shell.
The valence electrons determine the properties of the element and participate in the formation of bonds. The electrons of the d-orbital participate in the formation of bonds. So, to determine the valence electrons of a transition element, the last shell electrons have to be calculated with the d-orbital electrons.
How do you calculate the number of valence electrons in a zinc atom?
The valence electrons have 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.
The valence electrons of the transition element cannot be determined according to Bohr’s atomic model. This is because the valence electrons of the transition elements are located in the inner shell. However, the valence electrons of the transition element can be easily determined according to the Aufbau principle. Now we will learn how to determine the valence electron of zinc(Zn).
Step-1: Determining the total number of electrons in zinc
1st we need to know the total number of electrons in the zinc atom. To know the number of electrons, you need to know the number of protons in zinc. And to know the number of protons, you need to know the atomic number of the zinc 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 zinc 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 zinc atom. From the periodic table, we see that the atomic number of zinc(Zn) is 30. That is, the zinc atom has a total of thirty electrons.
Step-2: Need to do electron configuration of zinc
Step 2 is very important. In this step, the electrons of zinc have to be arranged. We know that zinc atoms have a total of thirty electrons. The first two electrons enter the 1s orbital and the next two electrons enter the 2s orbital. The next six electrons enter the 2p orbital. The p-orbital can have a maximum of six electrons. So, six electrons enter the 2p orbital.
The next eight electrons enter the 3s and 3p orbitals. The 3p orbital is now full, so two electrons enter the 4s orbital. We know that a d-orbital can have a maximum of ten electrons. Therefore, the remaining ten electrons enter the d-orbital. Therefore, the zinc electron configuration will be 1s2 2s2 2p6 3s2 3p6 4s2 3d10. Here, the d-orbital is filled with electrons.
Step-3: Determine the valence shell and calculate the total electrons
The third step is to diagnose the valence shell. The last shell after the electron configuration is called the valence shell(orbit). The total number of electrons in a valence shell is called valence electrons. But the valence electrons of the transition elements are located in the inner orbit.
For the transition element, the valence electron has to be determined by adding the total electrons of the d-orbital to the electron in the last shell of the atom. The last shell of zinc has two electrons(4s2) and the d-orbital has a total of ten electrons(3d10). Here, the d-orbital is filled with electrons and there are two electrons at the last energy shell. Therefore, the valence electrons of zinc(Zn) are two.
How many valence electrons does zinc ion(Zn2+) have?
The elements that have 1, 2, or 3 electrons in the last shell donate the electrons in the last shell during bond formation. The elements that form bonds by donating electrons are called cation. The zinc atom exhibits a Zn2+ ion. The zinc atom donates two electrons in the 4s orbital to form a zinc ion(Zn2+).
Zn – 2e– → Zn2+
Here, the electron configuration of zinc ion(Zn2+) is 1s2 2s2 2p6 3s2 3p6 3d10. This electron configuration shows that zinc ion(Zn2+) has three shells and the last shell has eighteen electrons. For this, zinc ions have a total of eighteen valence electrons.
How to determine the valency of zinc?
The ability of one atom of an element to join another atom during the formation of a molecule is called valency(valence). There are some rules for diagnosing valency. The number of electrons in an unpaired state in the last orbital after the electron configuration of an atom is called the valency of that element.
The oxidation state of zinc(Zn) is +2. The oxidation state of zinc +2 has been used in Zinc oxide(ZnO). The valency of zinc in this compound is 2. The oxidation states of zinc depend on the bond formation.