why are they shaped liked this
1)BF4- is a tetrahedral molecule
2)SF3+ is a Trigonal pyramidal molecule
3)ICI4- IS A SQUARE PLANER molecule
4IF5 IS A SQUARE pyramidal molecule
5)PF5 IS A TRIGNAL BIPYRAMIDAl molecule help Dr bob222
To understand why molecules have particular shapes, it is important to consider their molecular geometry. Molecular geometry is determined by the arrangement of the atoms around the central atom and the number of lone pairs present.
1) BF4- is a tetrahedral molecule: The central atom in BF4- is boron (B), and it is surrounded by four fluorine (F) atoms. Boron has three valence electrons, and each fluorine atom has seven valence electrons. To achieve stability, boron forms three sigma bonds with three fluorine atoms, and the fourth fluorine atom forms a coordinate covalent bond, donating its lone pair to the boron atom. These four regions of electron density, three sigma bonds and one lone pair, repel each other equally, resulting in a tetrahedral shape.
2) SF3+ is a trigonal pyramidal molecule: In SF3+, the central atom is sulfur (S), and it is surrounded by three fluorine (F) atoms. Sulfur has six valence electrons, and each fluorine atom has seven valence electrons. To achieve stability, sulfur forms three sigma bonds with three fluorine atoms, leaving one of its valence electron unpaired. The lone pair on sulfur creates an electron cloud, resulting in a trigonal pyramidal shape.
3) ICl4- is a square planar molecule: In ICl4-, the central atom is iodine (I), and it is surrounded by four chlorine (Cl) atoms. Iodine has seven valence electrons, and each chlorine atom has seven valence electrons. To achieve stability, iodine forms four sigma bonds with four chlorine atoms, leaving two lone pairs on iodine. The four regions of electron density, four sigma bonds and two lone pairs, repel each other, resulting in a square planar shape.
4) IF5 is a square pyramidal molecule: In IF5, the central atom is iodine (I), and it is surrounded by five fluorine (F) atoms. Iodine has seven valence electrons, and each fluorine atom has seven valence electrons. To achieve stability, iodine forms five sigma bonds with five fluorine atoms, leaving two lone pairs on iodine. The five regions of electron density, five sigma bonds and two lone pairs, repel each other, resulting in a square pyramidal shape.
5) PF5 is a trigonal bipyramidal molecule: In PF5, the central atom is phosphorus (P), and it is surrounded by five fluorine (F) atoms. Phosphorus has five valence electrons, and each fluorine atom has seven valence electrons. To achieve stability, phosphorus forms five sigma bonds with five fluorine atoms, resulting in a trigonal bipyramidal shape. The five regions of electron density, five sigma bonds, repel each other.
To determine the shapes, it is important to count the number of sigma bonds and lone pairs around the central atom while considering the concept of electron repulsion. Based on these factors, the specific shapes of these molecules can be determined.