If boron has two energy levels, then how many energy levels do the other two elements have?

Updated April 24, 2017

By Corina Fiore

The periodic table is organized into columns and rows. The number of protons in the nucleus increases when reading the periodic table from right to left. Each row represents an energy level. The elements in each column share similar properties and the same number of valence electrons. Valence electrons are the number of electrons in the outermost energy level.

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The number of electrons in each energy level is displayed on the periodic table. The number of elements in each row shows how many electrons it takes to fill each level. Hydrogen and helium are in the first row, or period, on the periodic table. Therefore, the first energy level can have a total of two electrons. The second energy level can have eight electrons. The third energy level can have a total of 18 electrons. The fourth energy level can have 32 electrons. According to the Aufbau Principle, electrons will fill the lowest energy levels first and build into the higher levels only if the energy level before it is full.

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Each energy level is made up of areas known as an orbital. An orbital is an area of probability in which electrons can be found. Each energy level, except for the first, has more than one orbital. Each orbital has a specific shape. This shape is determined by the energy the electrons in the orbital possess. Electrons can move anywhere within the shape of the orbital at random. The characteristics of each element are determined by the electrons in the orbital.

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The s-orbital is shaped as a sphere. The s-orbital is always the first to be filled in each energy level. The first two columns of the periodic table are known as the s-block. This means that the valence electrons for these two columns exist in an s-orbital. The first energy level only contains an s-orbital. For example, hydrogen has one electron in the s-orbital. Helium has two electrons in the s-orbital, filling the energy level. Because helium’s energy level is filled with two electrons, the atom is stable and does not react.

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The p-orbital begins to fill once the s-orbital has been filled in each energy level. There are three p-orbitals per energy level, each shaped like a propeller blade. Each of the p-orbitals holds two electrons, for a total of six electrons in the p-orbitals. According to Hund’s Rule, each p-orbital per energy level must receive one electron before earning a second electron. The p-block starts with the column containing boron and ends with the column of noble gases.

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The d- and f-orbitals are very complex. There are five d-orbitals per energy level, starting with the third energy level. The transition metals make up the d-orbitals. There are seven f-orbitals per energy level starting with the fifth energy level. The lanthanide and actinide make up the f-orbitals.

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Check out the blackboard. That box on the left has all of the information you need to know about one element. It tells you the mass of one atom, how many pieces are inside, and where it should be placed on the periodic table. In the next section we're going to cover electron orbitals or electron shells. This may be a new topic to some of you.

Electrons In The Shells

Take a look at the picture below. Each of those colored balls is an electron. In an atom, the electrons spin around the center, also called the nucleus. The electrons like to be in separate shells/orbitals. Shell number one can only hold 2 electrons, shell two can hold 8, and for the first eighteen elements shell three can hold a maximum of eight electrons. As you learn about elements with more than eighteen electrons you will find that shell three can hold more than eight. Once one shell is full, the next electron that is added has to move to the next shell.

So... for the element of BORON, you already know that the atomic number tells you the number of electrons. That means there are 5 electrons in an boron atom. Looking at the picture, you can see there are two electrons in shell one and three more in shell two.

Boron (B) is able to form compounds with chlorine (Cl) to create BCl3. Because of it's structure, boron is able to share it's three extra electrons with three separate chlorine atoms. If you look at the dot structure, you'll see that each of the chlorine atoms has eight electrons, making their shells full!

Borane is the name scientists have when one boron (B) atom bonds to three hydrogen (H) atoms. You can see that each of the hydrogen atoms now has two electrons, filling their outer shell. The boron atom has lost its three extra electrons, giving it a full shell as well.

Home Science Chemistry

boron group element, any of the six chemical elements constituting Group 13 (IIIa) of the periodic table. The elements are boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). They are characterized as a group by having three electrons in the outermost parts of their atomic structure. Boron, the lightest of these elements, is a metalloid. Aluminum, gallium, indium, and thallium are silvery white metals. Nihonium has only been produced as individual atoms in particle accelerators.

None of these elements was known in a pure state before modern chemistry isolated them. Very soon after a method had been found to produce it in commercial quantities, aluminum revolutionized industry. With further development of science and technology, specifically in nanotechnology, boron gained significant attention in industrial sectors as well. The other members of the group still have little commercial value. Some of the compounds of boron and aluminum, however, are indispensable in modern technology and have been widely used in many parts of the world throughout recorded history.

Periodic Table of the Elements

Test your bond with the periodic table of elements in this quiz on all 118 chemical elements and their symbols. You may be familiar with the chemical symbols for hydrogen and oxygen, but can you match such lower-profile elements as gadolinium and erbium with their corresponding symbols?

The use of a boron compound known as borax (sodium tetraborate, Na2B4O7∙10H2O) can be traced back to the ancient Egyptians, who used it as a metallurgical flux (a substance that aids the heat joining or soldering of metals), in medicine, and in mummification. During the 13th century Marco Polo introduced borax into Europe, but not until the mid-19th century, when vast deposits of borates were discovered in the Mojave Desert, did borax become relatively common. The ancient Egyptians, Greeks, and Romans used a compound of aluminum known as alum (the compound potassium aluminum sulfate) in dyeing as a mordant—i.e., a substance that fixes dye molecules to the fabric. Lapis lazuli, a rare dark blue mineral (the compound sodium aluminum silicate containing sulfur), has been widely used as a semiprecious stone throughout history. The metal aluminum was first isolated early in the 19th century, but it was not until a modern electrolytic process based on the use of bauxite ore had been developed that commercial production of aluminum became economically feasible. Three other boron group elements—gallium, indium, and thallium—were first detected spectroscopically (i.e., by analysis of the light emitted by or passed through substances containing the element) in the late 19th century. The existence and properties of gallium were predicted by a Russian chemist, Dmitry Ivanovich Mendeleyev, on the basis of the periodic table of the elements that he had developed; the ultimate discovery of gallium and the accuracy of his description of the properties of the then unknown element convinced scientists of the theoretical soundness of the table. Gallium is one of two metals (the other is cesium) whose melting points are low enough for them to turn to liquid when held in the hand. Nihonium was artificially produced in a particle accelerator in 2004.

Every element in the boron group has three electrons in its outermost shell (so-called valence electrons), and for each element there is a sharp jump in the amount of energy required to remove the fourth electron, reflecting the fact that this electron must be removed from an inner shell. Consequently, the elements of the group have maximum oxidation numbers of three, corresponding to loss of the first three electrons, and form ions with three positive charges.

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The apparently erratic way in which ionization energies vary among the elements of the group is due to the presence of the filled inner d orbitals in gallium, indium, and thallium, and the f orbital in thallium, which do not shield the outermost electrons from the pull of the nuclear charge as efficiently as do the inner s and p electrons. In Groups 1 and 2 (Ia and IIa), in contrast to the boron group, outer shell (always referred to as n) electrons are shielded in every case by a constant inner set of electrons, in the (n-1)s2(n-1)p6 orbitals, and the ionization energies of these Group-1 and Group-2 elements decrease smoothly down the group. The ionization energies of gallium, indium, and thallium are thus higher than expected from their Group 2 counterparts because their outer electrons, being poorly shielded by the inner d and f electrons, are more strongly bound to the nucleus. This shielding effect also makes the atoms of gallium, indium, and thallium smaller than the atoms of their Group 1 and 2 neighbours by causing the outer electrons to be pulled closer toward the nucleus.

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The M3+ state for gallium, indium, and thallium is energetically less favourable than Al3+ because the high ionization energies of these three elements cannot always be balanced by the crystal energies of possible reaction products. For example, of the simple, anhydrous compounds of thallium in its +3 oxidation state, only the trifluoride, TlF3, is ionic. For the group as a whole, therefore, the M3+ ionic state is the exception rather than the rule. More commonly the elements of the group form covalent bonds and achieve an oxidation state of three by promoting one electron from the s orbital in the outer shell (designated ns orbital) to an np orbital, the shift permitting the formation of hybrid, or combination, orbitals (of the variety designated as sp2). Increasingly down the group there is a tendency toward the formation of M+ ions, and at thallium the +1 oxidation state is the more stable one. The basicity (a property of metals) of the elements also increases in proceeding down the group, as shown by the oxides they form: boric oxide (formula B2O3) is acidic; the next three oxides, of aluminum, gallium, and indium (formulas Al2O3, Ga2O3, and In2O3) are either acidic or basic depending on the environment (a property called amphoterism); and thallic oxide (Tl2O3) is wholly basic.