Relationship between valence electrons and chemical properties

How Do an Element's Valence Electrons Relate to Its Group in the Periodic Table? | Sciencing

relationship between valence electrons and chemical properties

highest occupied energy level of an atom is filled with electrons, the atom is stable and not likely to react. The chemical properties of an element depend on the number of valence electrons. An electron transfer of electrons between atoms. Relationship between outer shell electrons and atomic reactivity. all the elements in the same group have very similar chemical properties. In chemistry, a valence electron is an outer shell electron that is associated with an atom, and The presence of valence electrons can determine the element's chemical properties, such as its valence—whether it may . A semiconductor has an electrical conductivity that is intermediate between that of a metal and that of a .

Now, what's the first thing you thought when you saw the Periodic Table? If you're like most people, the first thing you thought was probably something like, "Wow — that's a funny shape! Why is the Periodic Table shaped like that? Why is it lower in the middle? Why is it higher on either end? Why is there that odd-looking disconnected piece at the bottom? The Periodic Table doesn't look like a table at all! It turns out that the shape of the Periodic Table actually helps to tell us about the chemical properties of the different elements that exist in our world.

In this section, for example, you'll learn that elements in the same column of the Periodic Table have similar chemical properties. Later we'll take a look at how elements in the same row are related. Group 1A IA Elements Have One s Electron[ edit ] Remember that according to the Aufbau principle electrons are added to low energy orbitals first and then, as the low energy orbitals are filled up, electrons go into higher and higher energy orbitals.

When one atom reacts with another atom in a chemical reaction, it's the high-energy electrons that are involved. Since it's only the high-energy electrons that participate in a chemical reaction, it's only the high-energy electrons that we will concern us when we want to determine the chemical properties of a particular element.

Just how "high" in energy does an electron need to be to participate in a chemical reaction? Well, in most chemical reactions, the only electrons involved are the electrons in the highest energy level. In other words, the electrons with the highest value of n the principal quantum numberparticipate in chemical reactions, while the electrons with lower values of n are called "core electrons", are closer to the nucleus and, as a result, don't get involved.

The electrons with the highest value of n are known as valence electrons. Core electrons are also referred as non-valence electrons. Two different elements have similar chemical properties when they have the same number of valence electrons in their outermost energy level. Elements in the same column of the Periodic Table have similar chemical properties. So what does that mean about their valence electrons?

Elements in the same column of the Periodic Table have the same number of valence electrons — that's why they have similar chemical properties. Let's see if this is true for some of the elements in the first column of the Periodic Table. Example 1 — Hydrogen Write the electron configuration for hydrogen H. First, you need to find hydrogen on the Periodic Table.

Take a look at the Periodic Table above. You know that hydrogen is in the first column, and if you look carefully, you'll see that hydrogen also happens to be at the top of the first column. Neutral hydrogen will also have 1 electron. You need to write the electron configuration for an atom with 1 electron. As shown in the figure below, the diagonal rule applied to hydrogen H.

Therefore, we write the electron configuration for H: What is the highest principal quantum number that you see in hydrogen's electron configuration?

How do valence electrons affect the properties of atoms?

Hydrogen has 1 valence electron in an s orbital. Example 2 — Lithium Write the electron configuration for lithium Li.

First, you find lithium on the Periodic Table. Neutral lithium will also have 3 electrons.

Valency of an element, structure of the atom, class 9 science, chemistry

You need to write the electron configuration for an atom with 3 electrons. As illustrated in the figure below, the diagonal rule applied to lithium Li.

Therefore, we write the electron configuration for Li: What is the highest principal quantum number that you see in lithium's electron configuration? Lithium has 1 valence electron in an s orbital. Example 3 — Sodium Write the electron configuration for sodium Na. First, you find sodium on the Periodic Table. Neutral sodium will also have 11 electrons. You need to write the electron configuration for an atom with 11 electrons. As shown below, the diagonal rule applied to sodium Na.

Therefore, we write the electron configuration for Na: What is the highest principal quantum number that you see in sodium's electron configuration? Don't be fooled by the 2p6 orbitals. Sodium has 1 valence electron in an s orbital. If you look at the last line in Example 1, Example 2, and Example 3 you should notice a pattern.

Hydrogen has 1 valence electron in an s orbital Lithium has 1 valence electron in an s orbital Sodium has 1 valence electron in an s orbital In fact, all elements in the first column of the Periodic Table have 1 valence electron in an s orbital.

Therefore, we would expect all of these elements to have similar chemical properties — and they do. Hydrogen is special because it is the first element in the Periodic Table.

As a result, hydrogen has only one proton and one electron, which give it special chemical properties. Sometimes scientists don't include hydrogen in the first column of the Periodic Table, but instead give it its own "special" column to reflect its special properties — we won't do that here, but you should realize that hydrogen does not have all the same chemical properties as the rest of the elements in its column.

The elements in the first column of the Periodic Table other than hydrogen are known as Group 1A metals, or alkali metals. When you compare the chemical properties of these elements lithium, sodium, potassium, rubidium, cesium, and franciumwhat you'll notice is that they are all remarkably similar.

Group 1A elements are metals, silver-colored, and soft.

relationship between valence electrons and chemical properties

These elements are extremely reactive. Several of them explode if you put them in water. As pictured below, notice how the elements lithium Lisodium Naand potassium K all look alike.

Valence electron - Wikipedia

They are all soft, silver metals. Lithium Li Sodium Na Potassium K And finally, because they are so reactive, Group 1A elements are not found in their elemental form in nature — in other words, you don't find pure sodium or pure potassium in nature. How do you think the elements in the second column of the periodic table differ? Let's find out by taking a look at a few examples. Example 4 — Beryllium Write the electron configuration for beryllium Be.

First, you find beryllium on the Periodic Table.

relationship between valence electrons and chemical properties

Neutral beryllium will also have 4 electrons. You need to write the electron configuration for an atom with 4 electrons. As shown below, the diagonal rule applied to beryllium Be. Therefore, we write the electron configuration for Be: Beryllium has 2 valence electrons in an s orbital.

Example 5 — Magnesium Write the electron configuration for magnesium Mg. First, you find magnesium on the Periodic Table. Neutral magnesium will also have 12 electrons. You need to write the electron configuration for an atom with 12 electrons.

Therefore, the electron configuration for Mg: What is the highest principal quantum number that you see in magnesium's electron configuration? Magnesium has 2 valence electrons in an s orbital. You can probably guess the number and type of valence electrons in an atom of calcium Castrontium Srbarium Baor radium Ra. If you guessed 2 electrons in an s orbital, then you guessed right!

All elements in the second column of the Periodic Table have 2 valence electrons in an s orbital. The elements in the second column of the Periodic Table are known as Group 2A metals, or alkaline earth metals. As you might expect, because all Group 2A metals have 2 valence electrons in an s orbital, they all share similar chemical properties. Group 2A elements are metals, silver colored, and are quite reactive though they are not nearly as reactive as the Group 1A elements.

Group 3A IIIA Elements Have s and 1p Electrons[ edit ] All of the elements in the first column of the Periodic Table have 1 valence electron in an s sublevel and all of the elements in the second column of the Periodic Table have 2 valence electrons in an s sublevel.

Can you make any prediction about the valence electrons in the third column of the Periodic Table? Where is the third column of the Periodic Table? It turns out that there are really two different "third columns" in the Periodic Table.

Take a close look at the figure of the Period Table the first figure of this lesson. Can you spot the column labeled "3A"? Can you spot the column labeled "3B"? You need to note that there is an alternate way to name 3A elements; they can also be referred to as group 13 since these elements are in the 13th column of the Periodic Table.

Therefore, it obviously makes sense to discuss the 3A column first. Let's figure out how many valence electrons atoms in the 3A column have.

Example 6 — Boron Write the electron configuration for boron B. First, measuring weight is a tricky task, and many of the accepted weights of Mendeleev's day were not correct. Second, it turns out that atomic weight is not really the relevant parameter.

Today's periodic tables place the elements in order of their atomic number, which is the number of protons in the nucleus. In Mendeleev's time, protons had not yet been discovered. Elements and Chemical Properties Mendeleev wrote that "arrangement according to atomic weight corresponds to the valence of the element and to a certain extent the difference in chemical behavior.

Mendeleev combined the order of atomic weight with common valences to organize the elements in a table. That is, he organized the elements in groups according to their chemical characteristics. Because those properties repeat every so often, the result was a periodic table in which each vertical column, called a group, contains elements with similar characteristics, and each horizontal row, called a period, arranges the elements by weight, increasing from left to right and top to bottom.

Sciencing Video Vault Atomic Structure About 50 years after Mendeleev's first periodic table, scientists discovered the atom was built around a nucleus with positively charged protons and neutral neutrons -- both of which are relatively heavy. The positively charged nucleus is surrounded by a cloud of negatively charged electrons.

The number of protons -- also called the atomic number -- typically matches the number of electrons. It turns out that the number of electrons an element has largely determines its chemical properties.