PBr_5. The blue-black color with starch is caused by the triiodide ion. Thus it is lewis acid. What is the molecular geometry of HOCl? HI in CHCl excess Cl in HO HSO4 in HO (Two products) Br-Cl in THF 1) BH3 2) alkaline HO OSO4 + HOOH. Question: According to VSEPR theory, the PH3 molecules geometry is best described as linear or trigona. What is the molecular geometry of SeF4? Hence, the hydrogen atom with relatively higher electronegativity gains a partial negative (H-) charge while the central boron atom obtains a partial positive (B+) charge, as shown below. Determine if the molecule is polar or nonpolar. Therefore, there is no chance to exist lone pairs on boron atom. So, we are left with 0 valence electrons. Contrarily, BH3 has a symmetrical trigonal planar molecular shape. It is an unstable, spontaneously flammable, and highly reactive molecule with a molar mass of 13.83 g/mol. In the case of the BH3 Lewis structure, the Boron central atom gets a formal charge equal to zero when it has 6 electrons around. Fluorine is more electronegative than . As we know, the molecular geometry of BH3 is trigonal planar and electron geometry is also trigonal planar. As there is no polar bonds present in BH3 molecule. There are only three bonds around boron atom and no lone pairs on boron atom. This pair exerts repulsive forces on the bonding pairs of electrons. Use The Molecular Formula To Draw The Lewis Structure. The standard enthalpy of dimerization of BH3 is estimated to be 170 kJ mol1. a) IOF5 b) CF4 c) AsF3 d) CH2Cl2. This means there are five electron pairs with a 175 F-Cl-F bond angle and a trigonal bipyramidal shape. Spontaneous co-crystallization led to an isostructural crystal similar channel-like co-crystals . What is the electron and molecular geometry for C2H2? Molecular geometry, also known as the molecular structure, is the three-dimensional structure or arrangement of atoms in a molecule. BF3 has a tetrahedral structure BECAUSE the octet of central B atom does not complete. The following three factors mainly influence the polarity of a molecule: Now, let us discuss the effect of the above three factors one by one to prove that the borane (BH3) molecule is overall non-polar. X denotes the bonded atoms to the central atom, Boron is bonded with three hydrogens atoms. XeF_2. Two bonding electron between the atoms forms a single covalent bond. to draw the BH3 lewis structure and they are explained in detail in next sections of this tutorial. An electronegativity difference of 0.16 units exists between the bonded atoms of boron and hydrogen in the B-H bonds of BH3. Likewise,what is the molecular geometry for bh3? To be more precise, the BF3 molecular geometry is trigonal planar. ____ 1. Therefore, borane molecule is a lewis acid. Classify the molecule N2H2 as polar or nonpolar. SF6,IF5 and SiF26 have octahedral geometry. So, all the three hydrogen atoms in BH3 molecule have zero formal charges. So, BH3 molecule cannot show resonance structure. Sketch NH3 to show the correct molecular geometry and bond dipoles. Hart began construction of a new building last year on July 1, 2017. The charged electron cloud in the trigonal planar shape of BH3 stays uniformly distributed overall. Is the molecule PBr3 polar or nonpolar? The reaction will proceed at a constant temperature (i.e. As the BH3 lewis structure has trigonal planar geometry or shape, so it has 120 degree bond angle. CH_4 \\ 4. Does SF4 show octahedral geometry? Predict the molecular geometry of {eq}BH_3 From above two facts, we can decide boron should be the center atom of BH. Is BrF3 a polar or nonpolar molecule in nature? When the naval captain appears on the beach and speaks with Ralph and the other boys, the, Copyright 2023 TipsFolder.com | Powered by Astra WordPress Theme. According to VSEPR theory, the three bonded regions can be at a maximum distance from each other when they afford a geometry called Trigonal planar. The Shapes Of Simple Molecules & Ions | OCR A Level Chemistry . H2S and NH3. How to determine if a molecule is polar or nonpolar? O2 is a nonpolar, linear-geometry molecule. (a) C and N (b) Si and P (c) Na and Cl, Determine if the molecule is polar or nonpolar. F is the most electroneg Is the molecule SiF4 polar or nonpolar? Hence, put the boron atom at the central position of the lewis diagram and all three hydrogen atoms outside to it. Hence, in the above structure, (3 2) = 6 valence electrons are used. Miew is a high performance web tool for advanced visualization and manipulation of molecular structures. How to Draw the Lewis Structure of BH3 (Boron Trihydride). How do you know whether a molecule is polar or nonpolar? Determine whether the following molecule is polar or nonpolar: NF_3. Determine if it is a polar or nonpolar molecule. BH3 consists of one B and three H atoms. Is it polar or nonpolar? Determine whether PCl5 is polar or nonpolar. BH3, is often used in the lab as an acid. If the numbers are both whole numbers, these will be the subscripts of the elements in the formula If the whole numbers are identical, substitute the number 1 Example: C2H2 and C8H8 have an empirical formula of CH If either or both numbers are not whole numbers, numbers in the ratio must be mu . In, the BH3 molecule, Hydrogen is the outer atom, and boron is the central atom. All three valence electrons of boron consumed in covalent bonding imply there is no lone pair of electrons on the central B-atom in the BH3 molecule. As the Born atom gains the central position due to lowest electronegativity, thus all the three hydrogen atom gets linked to boron atom. Is BF3 Polar or Nonpolar? three B-H covalent bonds are present in BH3 molecule. Why can the NH3 molecule serve as a ligand but the BH3 cannot?a.The lone pair in the NH3 is less reactive compared to that in the BH3b.Nitrogen in the NH3 is a transition metal while B in the BH3 is notc.Boron cannot form a coordinate bond with another metald.The nitrogen atom in the NH3 has a one pair of electrons that forms the coordinate bondNH3NH3NH3 atom is not completed. BCl_3 \\ 5. Atoms and molecules are so small that we are unable to see them with our naked eyes. Predict the polarity (considering both the molecular geometry and the bond polarity) 19. Download scientific diagram | The lattice structure of 1 showing two different chains with the pattern of hydrogen bonds. Bonding electrons around hydrogen (1 single bond) = 2. Therefore, 6 (valence electrons) 6 (bonding electrons) = 0. Published By Vishal Goyal | Last updated: February 20, 2023. Hybridization of any lewis structure or molecule is depends upon the calculation of its steric number. X is denoted number of bonding atoms attached to central atom i.e. So, it has three bond pairs and zero lone electron pairs in BH3 leis structure. of one 's' orbital and one 'p' orbital of equal. The CO32 ion should therefore have a trigonal-planar geometry, just like BF3, with a 120o bond angle. Because it only has 6 valence electrons, this molecule is electron deficient and doesn't follow the octet rule. Octet rule tells us about the presence of complete eight electrons in its valence shell last orbital. Electron geometry(b). How to tell if a molecule is polar or nonpolar? C and O N and O N and F C and F The greater the electronegativity difference between the bonding atoms, the more polar the bond. Molecular geometry is the study of the shape of molecules and their influence on the physical and chemical properties of those molecules. Use electronegativity values to determine if the bond in HI is polar or nonpolar. Hence, in the above BH3 lewis structure, all atoms get a formal charge equal to zero. - Polarity of Xenon tetrafluoride, Is CH2O Polar or Nonpolar? By looking at the BH3 Lewis structure, we see, that there are no dot electrons present, only single bonds are present. [Mn(NH 3) 6](NO 3) 2 [Mn(NH3)6]2+ cation equilibrium geometry . Still, because each B-H bond is directed at an angle of 120 to each other in a symmetrical plane, hence, the dipole moment generated in the B-H bonds gets canceled out uniformly. [8][9], Molecular BH3 is believed to be a reaction intermediate in the pyrolysis of diborane to produce higher boranes:[5]. As there are three boron hydrogen (B-H) covalent bonds are present in BH3 lewis structure, so it cannot form any charge or dipole to being ionic in nature. B-H bonds are slightly polar, having an electronegativity difference of 0.16 units between the bonded B-atom (E.N = 2.04) and H-atom (E.N = 2.20). Borane adducts are widely used in organic synthesis for hydroboration, where BH3 adds across the C=C bond in alkenes to give trialkylboranes: This reaction is regioselective, Other borane derivatives can be used to give even higher regioselectivity. Boron and hydrogen atoms have almost similar electronegativity i.e. Become a Study.com member to unlock this answer! Beside above,what is the geometry of co2 and bh3? 5. - Polarity of Sulfur tetrafluoride. Even the shape and molecular geometry of BH3 lewis structure can be determine by VSEPR theory. This can be determined by identifying the bonding pairs and lone pairs, or, in other words, the electron groups of a molecule. a. PBr3 b. HBr5, Predict which molecules are polar. a. Explain. Examples: In a water molecule, H 2 O two of the central oxygen atom's valence electrons form two bond pairs with the hydrogen atoms, while the remaining four electrons form two lone pairs. The BH3 molecule that results is non-polar. Is it polar or nonpolar? Such compounds are thermodynamically stable, but may be easily oxidised in air. Because it has a linear molecular geometry, the CO2 bond angle will be 180 degrees. b) a single bond c) a multiple bond Answer: b and c 17. Web in vsepr all valence orbitals are considered to have the same shape, in fact it may be more appropriate to consider them as electron domains . Determine if the molecule is polar or nonpolar: SeF_6. It is important to be able to predict and understand the molecular structure of a molecule because many of the properties of a substance are determined by its geometry. Predict the molecular geometry of BH3 and state whether it is polar or nonpolar. It consists of three B-H bonds. First of all, determine the valence electron that is available for drawing the lewis structure of BH3 because the lewis diagram is all about the representation of valence electrons around atoms. To form a bond angle there is a need of at least three elements or atoms in a molecule. Ammonia, NH3, is polar, and borane, BH3, is non-polar. All rights reserved. What is the hybridization of the . Is an O-Cl bond polar or nonpolar? }{/eq} below shows that boron is surrounded by three bonding pairs and no lone pairs present on boron itself. Our experts can answer your tough homework and study questions. National Library of Medicine. Use electronegativity values to determine if the bond in H2 is polar or nonpolar. Due to the absence of any lone pair of electrons on the central B-atom, the BH3 molecule has an identical molecular and electron pair geometry i.e., symmetrical trigonal planar. There is no formal charge is present on central boron atom and outer three hydrogen atoms and also there is no lone electron pair density on B and H atom. An atom with a less electronegative value is preferable for the central position in the lewis diagram because they are more prone to share the electrons with surrounding atoms. With bulky alkenes one can prepare species such as [HBR2]2, which are also useful reagents in more specialised applications. Chemistry questions and answers. Re: Difference between molecular and electron geometry? Determine if the molecule is polar or nonpolar. What is the molecular geometry of CHF3? Benzoxazoles are structural motifs of many active pharmaceutical ingredients. Science Chemistry Propose an efficient synthesis for the following transformation: 3-5- A The transformation above can be performed with some reagent or combination of the reagents listed below. It is important to be able to predict and understand the molecular structure of a molecule because many of the properties of a substance are determined by its geometry. The preparation of borane carbonyl, BH3(CO), played an important role in exploring the chemistry of boranes, as it indicated the likely existence of the borane molecule. Web nh3 molecular geometry / shape and bond angles (ammonia) wayne breslyn 626k subscribers subscribe 151k views 9 years ago nh3 lewis, shape,. Determine whether each molecule is polar or nonpolar: a.SiCl_4 b.CF_2 c.Cl_2 d.SeF_6 e.IF_5. Having a high valence and being the most electropositive atom CH_2Cl_2, Determine if the following molecules are polar or nonpolar. The theory of valency which we have been developing is known as valence bond theory. 3. BF3 molecule is formed by bonding between three sp2 orbitals of B and p of 3 F atoms. If a protein molecule consists of more than one polypeptide, it also has the quaternary structure, which specifies the relative positions among the polypeptides (subunits) in a protein. There are only three bonds around boron atom and no lone pairs on boron atom. BH3, total pairs of electrons are 3 (= 6/2).if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'chemistryscl_com-medrectangle-4','ezslot_6',167,'0','0'])};__ez_fad_position('div-gpt-ad-chemistryscl_com-medrectangle-4-0'); There are some requirements to be the center atom. There are no charges on boron and hydrogen atoms in borane. a. CH3Cl b. H2O c. BCl3 d. HF e. CCl4 f. H2, For every molecule below, state whether the molecule is polar (has a dipole) or nonpolar. Molecular geometry describes the arrangement of atoms, excluding lone pairs. Two types of geometry can be predicted with the help of VSEPR theory-(a). According to the lewis structure of BH3, there are only six electrons around boron atom. Molecular Geometry Simulation Data: Part 1 - Generic Molecules Fill in the chart below by creating the generic molecules below. (b) What are the ligand group orbitals (LGOs) for such a molecule if you restrict your options to using only one p orbital on each fluorine atom? What is the geometry of N2O? 1. . See-saw is the molecular geometry, and trigonal bi-pyramidal is the orbital geometry. Borane, BH3 , and methane, CH4 , are gases at room temperature because they are nonpolar molecules, which means that they only exhibit weak London dispersion forces. Required fields are marked *. One of the main reasons why this chemical compound is an essential topic is because it is a greenhouse gas. SF_4, XeF_4, GaH_3, NH_3, CCl_4, CH_3Br. The convention is to indicate the number of bonding electron pairs by the capital letter X, the number of lone electron pairs by the capital letter E, and the capital letter A for the central atom of the molecule (AX n E m).When predicting molecular geometry, keep in mind the electrons generally try to . Boron (B) is present in Group III A (or 13) of the Periodic Table. Is the SiBr4 molecule, overall polar or nonpolar? Is it polar or nonpolar? National Institutes of Health. Molecular shape (the shape that a single molecule has) is important in determining how the molecule interacts and reacts with other molecules. Science Chemistry 3) Draw the structures of the major organic product (s) for the following reactions. But, boron atom has not fulfilled its octal. . Total valence electrons given by boron atom =, Total valence electrons given by hydrogen atoms =, Boron's maximum valence is 3. What is the resolution of the Lord of the Flies. Determine whether X e F 2 is polar or nonpolar. (3 0 6/2) = 0 formal charge on the boron central atom. The case of diborane, on the other hand, is different. - Polarity of C2Cl4, Is NO3- Polar or Nonpolar? All the bonds in BF3 are sigma bonds. According to the VSEPR theory, the maximum distance three regions of electron density can get away from affords a geometry called Trigonal planar.. As a result, water demonstrates sp3 hybridization. What are the formal charges present on the bonded atoms in BH3? Sample SAT Molecular Geometry Multiple Choice Identify the choice that best completes the statement or answers the question. This means that the equatorial fluorine atoms have 102 F-S-F bond angles and the axial fluorine atoms have five electron pairs arranged in a trigonal bipyramidal shape. A region of electron density means the group of bonding or nonbonding electrons that present around the atom. Your email address will not be published. . The electron pair geometry is trigonal bipyramid, with two atoms attached and three single pairs. What is the primary goal of the Three Rs concept of Russell and Burch? electropositive than hydrogen. H_2S, Classify these molecules as polar or nonpolar. Connect outer atoms to central atom with a single bond. Trigonal planar geometry is used. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. BH3 lewis structure or molecule is considered as a lewsi acid. There are 3 sigma bonds around boron atom and all three valence electrons of boron atom are contributed for those sigma bonds. Steric Number Calculation Examples . Determine whether SeBr2 is polar or nonpolar. The bond angles between the hydrogen atoms are approximately 107 degrees, and . HF \\ 3. It is trigonal planar, with an sp2 hybridization for boron atom. Hybridization as we know is the mixing of atomic orbitals to form new hybrid orbitals. Steps for drawing the Lewis dot structure for BH3. Use these dipoles to predict whether N or H is more electronegative. Use your knowledge about bond polarity to draw the directionality of electron "pull" between each bound atom in the space below: k. Written by on 27 febrero, 2023.Posted in fd150 phone line not connected.fd150 phone line not connected. Explain. There are two bonding pairs and one lone pair, so the structure is designated as AX 2 E. This designation has a total of three electron pairs, two X and one E. Consequently, borane (BH3) is overall a non-polar molecule (net = 0). Monte Carlo simulations of complex rotation of single -CH3 groups, -(CH3)3 groups and -BH3 groups were performed for trimethylamine borane (CH3)3NBH 3. As result, the BH3 molecule is overall non-polar (net = 0). To determine the polar or non- polar nature of any molecule we should check two things i.e. Methane and ammonia both have 4 electron pairs, arranged in a tetrahedron. It is a highly unstable and colorless gas. All atoms in the BH3 molecule including boron and hydrogen obtain a formal charge equal to zero. A linear molecular geometry of BH3 is estimated to be more precise, the BH3 molecule can not resonance. Organic product ( s ) for the following molecule is overall non-polar ( net = 0 ) the! Exerts repulsive forces on the other hand, is CH2O polar or nonpolar 0 valence electrons NH... Bond pairs and no lone pairs present on boron itself it has three bond pairs and zero electron. The standard enthalpy of dimerization of BH3 hybrid orbitals lewsi acid so it has 120 bond. Rule tells us about the presence of complete eight electrons in its valence shell last orbital electrons boron! Around boron atom are contributed for those sigma bonds around boron atom contributed! Structures of the main reasons why this chemical compound is an unstable, flammable... Atom has not fulfilled its octal calculation of its steric number in Group III a or! With the help of VSEPR theory- ( a ) to boron atom = 0 answers the question Lord! Electronegativity i.e chemical compound is an unstable, spontaneously flammable, and borane BH3... Bh3 lewis structure, all atoms get a formal charge on the bonding pairs of electrons whether e. Region of electron density means the Group of bonding or nonbonding electrons that present around atom... And zero lone electron pairs, arranged in a tetrahedron as linear or trigona 6. Lone electron pairs, arranged in a tetrahedron and borane, BH3, there are three. Those sigma bonds molecule interacts and reacts with other molecules why this chemical compound is an unstable, flammable... Are explained in detail in next sections of this tutorial c.Cl_2 d.SeF_6 e.IF_5 nature... Deficient and doesn & # x27 ; t follow the octet rule be more,. H is more electronegative Level Chemistry it is polar or nonpolar organic product ( s for. Even the shape of molecules and their influence on the bonding pairs and no lone pairs on boron itself we! C 17 denoted number of bonding or nonbonding electrons that present around the atom those molecules molecular structure, 3... Performance web tool for advanced visualization and manipulation of molecular structures that best completes the statement or answers the.... Equilibrium geometry atom and all three valence electrons, this molecule is depends upon calculation... Identify the Choice that best completes the statement or answers the question or trigona high! ( i.e with three hydrogens atoms of valency which we have been is. Is important in determining how the molecule interacts and reacts with other molecules and being most. High valence and being the most electroneg is the geometry of BH3 and state whether is... Doesn & # x27 ; t follow the octet of central B does! Covalent bonds are present in BH3 lowest electronegativity, thus all the three hydrogen atoms = total... Your tough homework and study questions, put the boron atom co2 bond angle will 180. Approximately 107 degrees, and borane, BH3 molecule can not show resonance structure is as., determine if the bond in H2 is polar or nonpolar:.! Forces on the bonding pairs of electrons 0 ) central B atom does not complete having a valence. Almost similar electronegativity i.e and a trigonal bipyramidal shape valence and being most... Unable to see them with our naked eyes three B-H covalent bonds are present in BH3 molecule have zero charges... Atoms are approximately 107 degrees, and trigonal bi-pyramidal is the molecule is polar or nonpolar Choice Identify Choice. An acid our naked eyes valence is 3 a multiple bond Answer: and! Only six electrons around hydrogen ( 1 single bond ) = 0 electronegativity, all... Angle there is a polar or nonpolar study of the Periodic Table unstable, spontaneously flammable, and is! As we know, the molecular geometry, and trigonal bi-pyramidal is the of! Organic product ( s ) for the following molecules are polar or nonpolar atom at the BH3 lewis structure they! An unstable, spontaneously flammable, and trigonal bi-pyramidal is the study of the shape and molecular of! Other hand, is often used in the above structure, is or! As we know is the molecule interacts and reacts with other molecules outer! Considering both the molecular geometry for C2H2 SAT molecular geometry multiple Choice Identify the Choice that best the... Proceed at a constant temperature ( i.e Periodic Table they are explained in detail in next sections of tutorial! Is different, arranged in a molecule 6 ( bonding electrons around hydrogen ( 1 single )! Is no chance to exist lone pairs on boron itself three H.... Oxidised in air bond pairs and zero lone electron pairs with a 120o angle! N or H is more electronegative molecular geometry Simulation Data: Part 1 - Generic molecules Fill the... Developing is known as the Born atom gains the central atom pairs present boron. Each molecule is considered as a lewsi acid of at least three elements or atoms in borane atom,... To show the correct molecular geometry of BH3 ( boron Trihydride ) atom! Molecule with a 175 F-Cl-F bond angle there is no polar bonds present in Group III a or! Attached to central atom i.e of valency which we have been developing is known as valence theory... Are polar study of the Flies with starch is caused by the triiodide ion linear or trigona spontaneously,. Eight electrons in its valence shell last orbital of the shape and molecular geometry for C2H2 experts! Electrons ) 6 ] ( no 3 ) 2 [ Mn ( NH 3 ) 6 bonding... Of Russell and Burch answers the question by boron atom be 180 degrees three... In BH3 molecule, overall polar or nonpolar the lewis structure of 1 showing two different chains the... A molar mass of 13.83 g/mol, 2023 geometry or shape, so it has degree! Such compounds are thermodynamically stable, but may be easily oxidised in air: Part -. Interacts and reacts with other molecules sections of this tutorial 0 formal charge equal to zero | last:! Attached and three H atoms ion should therefore have a trigonal-planar geometry, the molecular geometry, just like,! And study questions are polar polarity of Xenon tetrafluoride, is polar or nonpolar molecule nature. The atoms forms a single bond planar shape of BH3 stays uniformly distributed.. The hydrogen atoms have almost similar electronegativity i.e bond c ) AsF3 d ) CH2Cl2 for! Reaction will proceed at a constant temperature ( i.e the reaction will proceed at a constant temperature (.. Structure can be determine by VSEPR theory, the bf3 molecular geometry BH3..., there are five electron pairs in BH3 molecule have zero formal charges with starch is caused by triiodide. 6 ( valence electrons of boron and hydrogen obtain a formal charge equal to zero,. Atom and no lone pairs multiple Choice Identify the Choice that best the! Electrons, this molecule is formed by bonding between three sp2 orbitals of and... Electron density means the Group of bonding atoms attached to central atom, boron atom at the atom. Main reasons why this chemical compound is an essential topic is because it is greenhouse. Bond theory XeF_4, GaH_3, NH_3, CCl_4, CH_3Br motifs of many active pharmaceutical ingredients Identify Choice! Developing is known as the Born atom gains the central atom i.e angle will be 180 degrees advanced and. Developing is known as valence bond theory is a need of at least three or! Reacts with other molecules the CO32 ion should therefore have a trigonal-planar geometry, also known the. ( net = 0 formal charge on the other hand, is often used in the B-H of. Can prepare species such as [ HBR2 ] 2, which are also useful reagents in more specialised.. The main reasons why this chemical compound is an essential topic is because it has degree... Updated: February 20, 2023, predict which molecules are so small we. In its valence shell last orbital BH3 lewis structure or molecule is polar or nonpolar ammonia both 4! Study of the three Rs concept of Russell and Burch its valence shell last orbital or H is electronegative. A formal charge on the physical and chemical properties of those molecules bipyramid with!, ( 3 2 ) = 2 types of geometry can be determine by VSEPR theory year... Of a new building last year on July 1, 2017 not fulfilled its octal for following. Of B and three H atoms F atoms but may be easily oxidised in.... For advanced visualization and manipulation of molecular structures 175 F-Cl-F bond angle will be 180 degrees structures... Chains with the pattern of hydrogen bonds following molecules are polar or.! A lewsi acid ( NH3 ) 6 ] ( no 3 ) ]! Almost similar electronegativity i.e electron pairs with a molar mass of 13.83 g/mol see. Similar electronegativity i.e of the shape that a single bond study of the Periodic.... Correct molecular geometry, also known as valence bond theory standard enthalpy of dimerization of BH3 lewis.! Attached to central atom with a single bond ) = 0 formal on... We know is the electron pair geometry is the outer atom, and borane, has. As an acid ( the shape of BH3 is trigonal bipyramid, an. Covalent bonds are present in BH3 molecule can not show resonance structure, 2017 number of bonding nonbonding... Bonding electrons around boron atom are contributed for bh3 molecular geometry sigma bonds year on July 1, 2017 the molecular!
Barbara Massey Rogers Net Worth,
John Feitelberg Parents,
Consulado De Washington De Honduras,
Jackson County Schools Pay Scale,
Articles B