You can look at the atoms like puzzle pieces where you are trying to fit together the electrons so that everyone that needs an octet has one. Thus, the electron-pair geometry is tetrahedral and the molecular … These are of the form AX 2 E 2 and have bent angles, which in the case of water are 104.5 o C \(\PageIndex{6}\): Molecules like water have tetrahedral electronic geometry and bent molecular geometry. The bond angle is 104.5 0 which is less than ideal for tetrahedral geometry (109.5 0) due to presence of two lone lone pairs. Because water has a slightly negative end and a slightly positive end, it can interact with itself and form a highly organized 'inter-molecular' network. Based on the Lewis structure above the AXE notation would be AX2E2, meaning there are a total of four substituents (2 atoms and 2 lone pair) coming off of the central atom. The resulting molecular shape is bent with an H-O-H angle of 104.5°… Therefore this molecule is polar. The geometry of the molecule can be described in two ways: 1) Electron Geometry–the geometry that takes lone pairs and atoms into account (hint: there is are only 5 different electron geometries) and 2) Molecular Geometry– the geometry that ignores lone pairs and only takes atoms into account (there are 13 of these). Some background on VSEPR theory:  Valence Shell Electron Pair Repulsion Theory (VSEPR) suggests that molecular geometry is based purely on the number of atoms and lone pairs attached to a central atoms AND that electrostatic repulsions will place these atoms and lone pairs as far away from each other as geometrically possible. See the answer. (See below for an explanation of the difference between the two geometries) The bond angle for this … A good rule of thumb is to determine the electron geometry first then assume that any lone pairs of electrons are along the equator of the central atom. Based on VSEPR Theory (Valence Shell Electron Pair Repulsion Theory) the electron clouds around these atoms will repel each other. What is the electron pair geometry … Which of the following most likely represents the molecular geometry of water? In this example, oxygen is the central atom. This decrease in the angle leads to a bent structure. The shape of the molecule is bent although the geometry is tetrahedral. Molecular Geometry Lab - Part II(b) NOTE: Click on the buttons below the structures to rotate the molecules. Step 3: Use the VSEPR table to determine the H2O electron geometry: four substituents is tetrahedral. Hydrogen Selenide on Wikipedia. According to the VSEPR theory, the lone pairs of electrons repel each other, but as the Sulfur atom is less electronegative, the bond angle decreases to 104.5 degrees. A frequently asked question with VSEPR is whether or not a student should memorize the different molecular geometries an atom could take. b) molecular geometry of H2O. Can you predict the electronic geometry, molecular geometry … This is linear geometry… quick explanation of the molecular geometry of H2O (Water) including a description of the H2O bond angles This corresponds to the tetrahedral shape whereas square planar has dsp^2 hybridized state. The molecular geometry of SeH 2 is bent with asymmetric charge distribution on the central atom. An example of linear electron pair and molecular geometry is BeH 2. The electron-pair geometry provides a guide to the bond angles of between a terminal-central-terminal atom in a compound.