What number of valence electrons does Selenium (Se) possess?

What is the valency of selenium Valence electrons

Selenium is the 34th element in the periodic table. Selenium is the element in group 16 and its symbol, ‘Se’, is its symbol. Selenium creates bonds via its valence electrons . This article will discuss in detail the valence elements of selenium. This article will hopefully help you to understand more about it.

Selenium-valence electrons study can be found here for a better understanding of the element. Further research can be done on the important features of this element. Selenium is a recognized chemical element in the chemistry branch.

trace levels of selenium are required for many animal and human cells. However, both elemental selenium and (especially), selenium salts can cause selenosis. Selenium is found in many multivitamins and infant formulas. It is also listed in many dietary supplements and infant formulas. There are different requirements for Selenium in plants. Some plants need a large amount while others do not.


In 1817, the Swedish chemist Jons Jacob Berzelius noticed a red substance that was formed from Sulfide Ores from Falun (Sweden). The red material was discovered to be an element by the Moon and the Selene chemists who investigated it the next year. Berzelius found an iron ore that had a high content of selenium, just days before he presented his report to world scientific societies. He gave the ore the name eucairite which means “just right in time” and demonstrates his sense of humor.

Place of Selenium (Se) in the periodic table

Place of Selenium (Se) in the periodic table

Selenium Health effects

Selenium can only be obtained through food. It is found in cereals, grains and meats. For good health, the body needs to have a certain amount of selenium every day. Most foods contain enough selenium to prevent diseases caused by a shortage.

There are many ways that humans can be exposed. Selenium is either in food or drinking. Or, when we come into contact with soil or air with high levels of selenium. Selenium is a very common element in nature and is easily found in our environment. Selenium absorption through food might be higher than usual in certain cases. This is because many selenium rich fertilizers were used on farmland in recent years.

Selenium Facts

Read key information and facts about element Selenium

Atomic Weight78.96
Atomic SymbolSe
Atomic Number34
Classificationother nonmetal
Group in Periodic Table16
Electronic Configuration[Ar] 3d10 4s2 4p4
Period in Periodic Table4
Block in Periodic Tablep-block
Group Name oxygen family
Boiling Point221 °C
Melting Point221 °C
Electronic Shell Structure[2, 8, 18, 6]
CAS NumberCAS7782-49-2

Selenium (Se) – Periodic Table (Element Information & More)

Selenium (Se) – Periodic Table (Element Information & More)


Selenium can be used to add color to glass, but it is also used in other ways. Some selenium compounds will decolourize glass. Others will give it a deep, reddish colour. It can also be used in architectural glass to reduce sunlight exposure, giving it a bronze hue. Selenium is used in the production of pigments for ceramics as well as paint and plastics.

Selenium is capable of both a photovoltaic and photoconductive actions. This converts light to electricity, while the electrical resistance decreases with increasing illumination. It is useful in photocells as well solar cells and photocopiers. It is used extensively in rectifiers because it can convert AC electricity to DC electricity.It is harmful to the scalp and can cause dandruff. Therefore, some shampoos that are anti-dandruff contain it. Selenium is also an additive for stainless steel.

Biological function

Selenium, an essential trace element, is important for many species, including humans. About 14 milligrams of Selenium are found in our bodies. Every cell in a human’s body contains more than one million selenium atoms.Too little or too much selenium could cause serious health problems. Selenium in excess can be carcinogenic or teratogenic, which disrupts the development of embryos and foetuses.

What are the valence elements of selenium and what do they mean?

Selenium is the third element in group 16. The number of electrons in the shell’s last orbit (valence electrons) is the total number. The valence electrons are the total number of electrons within the shell that has been formed by the selenium electron configuration is called. The properties of an element are determined by the valence electrons. They also participate in the formation bonds.

What number of protons and electrons does Selenium have?

The nucleus can be found in the middle of an atom. The nucleus is home to protons and neutrons. The atomic number for selenium is 34. The number of protons in a substance is called the atomic number. The number of protons found in selenium is therefore thirty-four. The nucleus contains a circular shell that houses electrons equal to protons. A selenium atom can have a total number of 34 electrons.

Valence is the ability of an atom of a chemical element to form a certain number of chemical bonds with other atoms. It takes values from 1 to 8 and cannot be equal to 0. It is determined by the number of electrons of an atom spent to form chemical bonds with another atom. The valence is a real value. Numerical values of valence are indicated with roman numerals (I,II, III, IV, V, VI, VII, VIII).

How can you find out the number of valence neutrons in a selenium-atom atom?

These are the steps to determine the valence electron. One of these is the electron configuration. Without an electron configuration, it is impossible to determine the valence of an electron. It is easy to determine the electron configuration of all elements.

However, it is possible to identify valence electrons by placing electrons according the Bohr principle. We will now learn how to identify the valence electron in selenium.

Finding the total number electrons in selenium

First, we must know the number of electrons present in the selenium-atom. You need to know how many protons are in selenium to determine the number electrons. To know the number protons, you must know the atomic number for the element of selenium.

A periodic table is required to determine the atomic number. The periodic table contains the atomic numbers of the selenium elements. The number of protons is called the atomic number. The nucleus also contains electrons that are equal to protons.

This means that we can now say that the number of electrons in the selenium-atom atom is equal to its atomic number. The atomic number for selenium is 34, as can be seen from the periodic table. This means that the total number of electrons in the selenium atom is 34.

The terms “oxidation degree” and “valence” may not be the same, but they are numerically almost identical. The conditional charge of an atom’s atom is called the oxidation state. It can be either positive or negative. Valence refers to the ability of an atom form bonds. It cannot have a negative value.

You will need to perform electron configurations of selenium

Important step 2. This step involves the arrangement of electrons in selenium. The total number of electrons in selenium atoms is thirty-four. The electron configuration of selenium shows there are two electrons within the K shell, eighteen electrons in L shell and six electrons in N shell.

This means that the first shell of selenium contains two electrons, while the second shell contains eight electrons. The third shell contains eight electrons, and the third shell has 18 electrons. The fourth shell contains six electrons. There are two shells of selenium with eight electrons each: 2, 8, 18 and 6.

  1.  The valence is a numerical characteristic of the ability of atoms of a given element to bond with other atoms.
  2. The valence of hydrogen is constant and equal to one.
  3. The valence of oxygen is also constant and equal to two.
  4. The valence of most of the other elements is not constant. It can be determined by the formulas of their binary compounds with hydrogen or oxygen.

Calculate the total electrons and determine the valence shell

The third step is to determine the valence. The valence shell is the last shell after the electron configuration. The total number or valence electrons of all electrons within a valenceshell is called the valence electrons. The electron configuration indicates that the last shell of selenium contains six electrons. The valence electrons for selenium (Se) have six.

How do you calculate the number of valence electrons in a selenium atom

What is the valency for selenium?

Valency (or valence) is the ability of an atom of an element in a molecule to join another atom during formation. There are a few rules that can be used to determine if valency is being detected. The valency of an element is the number of electrons found in an unpaired state in a last orbit after an electron configuration.

In the ground state, the correct electron configuration for selenium (Se) will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4px2 4py1 4pz1. This electron configuration shows us that the last shell of a selenium atom contains two unpaired electrons. In this example, the valency for selenium is 2. The electron configuration of an element in its excited state determines the element’s valency.

What is the valency of selenium

The selenium-atom absorbs energy when it is excited. An electron in the 4p orbital will then jump to the 5s orbital. The electron configuration of Se* in an excited state is therefore 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4px1 4py1 4pz1 5s1 selenium contains four unpaired electrons. In this example, the valency for selenium is 4.

The oxidation states of selenium are -2, +2,+4, or +6. Selenium trioxide (SeO 3) has used the oxidation state for selenium +6. This compound has a valency of 6. The bond formation determines the oxidation states for selenium.

What number of valence electrons does the selenium ion (Se2) contain?

During bond formation, elements with 5, 6, or 7 electrons receive electrons from the shell that contains them. Anions are elements that have electrons and can form bonds. The last shell of selenium is given two electrons during the formation of a bond and becomes a selenium-ion (Se 2-). This is why selenium can be called an anion element.

How many valence electrons does selenium ion(Se2-) have

The electron configuration for selenium (Se2) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6. This electron configuration shows the four shells of the selenium (Se2-) and eight electrons in the last shell. The selenium-ion (Se2-) has also acquired the electron configuration from krypton. The valence electrons for selenium (Se2) have eight electrons in their last shell.


Alexander Stephenson

Candidate of Chemical Sciences, editor-in-chief of Guide-scientific.com. Lecturer at several international online schools, member of the jury of chemistry competitions and author of scientific articles.

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