How to draw BeF2 Lewis Structure? - Science Education and Tutorials

Drawing BeF2 Lewis Structure is very easy. Here in this post, we described step by step method to construct BeF2 Lewis Structure.

Table of Contents

Key Points To Consider When Drawing The BeF2 Lewis Structure

A three-step approach for drawing the BeF2 Lewis structure can be used. The first step is to sketch the Lewis structure of the BeF2 molecule, to add valence electron around the Beryllium atom; the second step is to valence electron to the two fluorine atoms, and the final step is to combine the step1 and step2 to get the BeF2 Lewis Structure.

The BeF2 Lewis structure is a diagram that illustrates the number of valence electrons and bond electron pairs in the BeF2 molecule. The geometry of the BeF2 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which states that molecules will choose a BeF2 geometrical shape in which the electrons have from one another.

Finally, you must add their bond polarities to compute the strength of the Be-F bond (dipole moment properties of the BeF2 molecule). The Beryllium-fluorine bonds in beryllium fluoride (BeF2), for example, are polarised toward the more electronegative fluorine, and because both bonds have the same size and opposite to each other, their sum is zero due to the BeF2 molecule’s bond dipole moment, and the BeF2 molecule is classified as a nonpolar molecule.

The molecule of beryllium fluoride (with linear geometry) is tilted at 180 degrees and has a difference in electronegativity values between fluorine and beryllium atoms, with beryllium’s pull being less than fluorine’s terminal in the BeF2 molecule. As a result, it has no dipole moment. The BeF2 molecule has no dipole moment due to an equal charge distribution of negative and positive charges.

BeF2 Lewis Structure:

The central atom is beryllium, which is bordered on two terminals with fluorine atoms. Beryllium has two outermost valence electrons, indicating that it possesses two electrons in its outermost shell, whereas fluorine only has seven valence electrons in its outermost shell. To complete the octet of the fluorine atom, a fluorine terminal atom requires one electron. If you’re interested in learning more about the fluorine octet rule, please see our previous post.

Two fluorine atoms establish covalent connections with the beryllium atom as a result, leaving the beryllium atom without any lone pairs. There are no lone pairs on the beryllium central atom that resist the bond pairs of the two Be-F. According to VSEPR theory, no electronic repulsion leads the BeF2 molecule to take on a linear molecular shape like NO2+ and CS2.

The BeF2 molecule’s Be-F bonds are arranged in a symmetrical order around the linear geometry, giving rise to the linear BeF2 shape. The BeF2 molecule has a linear molecular geometry because there is no electrical repulsion between them.

Electronegative Difference Calculation BeF2 Molecule:

Beryllium has an electronegativity of 1.57, while fluorine has an electronegativity of 3.98 in the BeF2 molecule. The difference in electronegativity can be estimated using the method below.

The electronegative value difference between beryllium and fluorine
Electronegativity value of beryllium = 1.57
Electronegativity value of fluorine= 3.98
Difference of electronegativity value between beryllium and fluorine= 3.98 – 1.57 = 2.41
Electronegativity difference between Be-F bond calculation of BeF2 molecule

Due to the difference in electronegativity value of greater than 0.5, the Be-F bond of the BeF2 molecule becomes polar. Because of this difference in electronegativity, the BeF2 molecule’s Be-F bond becomes polar. The electronegativity of an atom is the strength with which it may attract bound electron pairs to its side. The polarity of BeF2 is discussed in our previous post.

As a result, the Be-F bond’s dipole moment is high due to the polarization of the bonds, and all Be-F bonds’ dipoles are faced opposite to each other in the linear geometry. The BeF2 molecule’s total dipole moment is predicted to be 0 D. It has a partial negative charge for fluorine atoms and a partial positive charge for the central beryllium atom.

The electron dot structure of the BeF2 molecule is also known as the BeF2 Lewis structure. It determines the number of outermost valence electrons as well as the electrons engaged in the BeF2 molecule’s bond formation. The outermost valence electrons of the BeF2 molecule must be understood while considering the Lewis structure of the molecule.

The beryllium atom is the middle element in BeF2 molecular geometry, with two electrons in its outermost valence electron shell, whereas the fluorine atom has seven electrons in its outermost valence electron shell.

The BeF2 molecule has a total of 16 valence electrons as a result of the foregoing reasoning. With the core central beryllium atom, the two-terminal fluorine atoms form covalent bonds, leaving the beryllium atom with no lone pairs on it.

The linear geometry and structure of the BeF2 molecules are similar to that of the carbon disulfide (CS2) molecule because no lone pairs of central beryllium atoms create interaction with Be-F bond pairs. The bond angle of the F-Be-F bond is approximately 180 degrees. The Be-F bond length is 181 pm(picometer).

To sketch the BeF2 Lewis structure by following these instructions:

Step-1: BeF2 Lewis Structure

To calculate the valence electron of each atom in BeF2, look for its periodic group from the periodic table. The alkaline earth metal and halogen families, which are the second and 17th groups in the periodic table, are both made up of beryllium and fluorine atoms. In their outermost shells, beryllium and fluorine have two and seven valence electrons, respectively.

Because beryllium and fluorine are members of the periodic table’s alkaline earth metals and halogen family groups, their valence electrons are two and seven, respectively.

Calculate the total number of electrons in the BeF2 molecule’s outermost valence shell. The first step is to determine how many electrons are in the BeF2 Lewis structure’s outermost valence shell. An electron in an atom’s outermost shell is known as a valence electron. It is represented by dots in the BeF2 Lewis diagram. The BeF2 molecule’s core carbon atom can be represented as follows:

Total outermost valence shell electron of beryllium atom in BeF2= 2
Total outermost valence shell electron of fluorine atom in BeF2= 7
The BeF2 molecule has one central beryllium atom and two fluorine atoms. Then the total outermost valence shell electrons can be calculated as follows
∴ Total outermost valence shell electrons available for BeF2 Lewis structure( dot structure) = 2 +2*7= 16 valence electrons in BeF2
calculation of total valence electron of BeF2 molecule

Choose the atom with the least electronegative value atom and insert it in the center of the molecular geometry of BeF2. We’ll choose the least electronegative value atom in the BeF2 molecule to place in the center of the BeF2 Lewis structure diagram in this phase. The electronegativity value in periodic groups grows from left to right in the periodic table and drops from top to bottom.

Step-2: BeF2 Lewis Structure

As a result, Beryllium is the first atom in the periodic table’s alkaline earth metal family group. fluorine is the first member of the halogen family. The electronegative value of a beryllium atom is lower than that of a fluorine atom. Furthermore, Beryllium has a two electrons limit since fluorine is the most electronegative element in the BeF2 molecule.

In a BeF2 Lewis structure diagram, the beryllium atom can be the center atom. As a result, central beryllium in the BeF2 Lewis structure, with all two fluorines arranged in the two-terminal of linear geometry.

Step-3: BeF2 Lewis Structure

Connect the exterior and core central atom of the BeF2 molecule with two single bonds (Be-F). In this stage, use two single bonds to connect all two fluorine atoms on the outside of the BeF2 molecule to the central beryllium atom in the middle.

Count how many electrons from the outermost valence shell have been used in the BeF2 structure so far. Each Be-F bond carries two electrons because each beryllium atom is connected to two fluorine atoms by two Be-F bonds. Bond pairings are what they’re called.

So, out of the total of 16 valence electrons available for the BeF2 Lewis structure, we used 4 for the BeF2 molecule’s two single (Be-F) bonds. The BeF2 molecule has no lone pair electrons in the center beryllium. We don’t need to put the extra electron in the molecular geometry of BeF2.

Place the valence electrons in the Be-F bond pairs starting with the core beryllium and two fluorine atoms in the BeF2 molecule. In the BeF2 Lewis structure diagram, we always begin by introducing valence electrons from the central beryllium atom. As a result, wrap around the central beryllium atom’s bond pair valence electrons first.

Beryllium requires 4 electrons in its outermost valence shell to complete the molecular stability. Beryllium already shares 4 electrons thanks to the two single bonds. Then place the valence electron in the fluorine atom, it placed around seven electrons. Totally, 12 valence electrons were placed on the two fluorine atoms of the BeF2 molecule.

We’ve positioned four electrons around the central beryllium atom, which is represented by a dot, in the BeF2 molecular structure above. The beryllium atom completes its molecular stability in the BeF2 molecule because it possesses 4 electrons in its outermost valence shell.

Count how many outermost valence shell electrons have been used so far using the BeF2 Lewis structure. Four electrons are shown as dots in the BeF2 chemical structure, whereas two single bonds each contain two electrons. The outermost valence shell electrons of the BeF2 molecule are 4 + 12= 16 as a result of the calculation.

So far, we’ve used 16 of the BeF2 Lewis structure’s total eight outermost valence shell electrons.

Complete the middle beryllium atom stability and, if necessary, apply a covalent bond. The core atom in the BeF2 Lewis structure is beryllium, which is bonded to the fluorine atoms by two single bonds (Be-F). With the help of two single bonds, it already shares four electrons. As a result, fluorine follows the octet rule and has eight electrons surrounding it on the two terminals of BeF2.

How to calculate the formal charge in BeF2 Lewis Structure?

The formal charge on the BeF2 molecule’s beryllium central atom often corresponds to the actual charge on that beryllium central atom. In the following computation, the formal charge will be calculated on the central beryllium atom of the BeF2 Lewis dot structure.

To calculate the formal charge on the central beryllium atom of the BeF2 molecule by using the following formula:
The formal charge on the beryllium atom of BeF2 molecule= (V. E(Be)– L.E(Be) – 1/2(B.E))
V.E (Be) = Valence electron in beryllium atom of BeF2 molecule
L.E(Be) = Lone pairs of an electron in the beryllium atom of the BeF2 molecule.
B.E = Bond pair electron in Be atom of BeF2 molecule
calculation of formal charge on beryllium atom in BeF2 molecule

The beryllium core atom (two single bonds connected to fluorines) of the BeF2 molecule has two valence electrons, zero lone pair electrons, and four bonding electrons. Put these values for the beryllium atom in the formula above.

Formal charge on beryllium atom of BeF2 molecule = (2- 0-(4/2)) =0

In the Lewis structure of BeF2, the formal charge on the central beryllium atom is zero.

Summary:

In this post, we discussed the method to construct the BeF2 Lewis structure. Need to remember that, if you follow the above-said method, you can construct molecular dot structure very easily.