A Short Note on Linear Shape of Molecule

A molecule shape is a three-dimensional arrangement of atoms. it is in space around a central atom. The three-dimensional shapes of small molecules can easily be predicted by applying (VSEPR) i.e.., VALENCE SHELL ELECTRON PAIR REPULSION THEORY. 

What do you mean by linear molecule?

A linear molecule is a molecule where the atoms are aligned in a straight line i.e., at an angle of 180° . Unlike ionic compounds, the shape of a molecule is determined by using the concept of valence shell electron pair repulsion theory (VSEPR). This concept talks about the covalent bonds, which are composed of negatively charged electrons, which tend to repel one another.

When elements combine, two types of bonds are formed between them

• Ionic bonds
• Covalent bonds

The name of this linear molecule came from the observation that all the atoms are aligned in a line. For example, to understand a straight line forming 180° , hold your arms as far as apart from each other, making 180° the same as linear molecules. A linear shape of a molecule is taken by molecules when bonding pairs are opposite to each other at the ends in a straight line forming exactly 180°.  A linear molecule shape is also an asymmetric molecule which makes it non-polar. 

A linear molecule can happen in both cases, either when the molecule contains two atoms or when a molecule contains three atoms. In the case of two atoms, those two atoms form a straight line linear molecule and in the case of three molecules, those three molecules form a straight line linear molecule. For example,  carbon dioxide, acetylene, and hydrogen cyanide. 

Molecules having linear electron-pair geometries contain sp hybridization at the central atom. An example of such a linear electron pair and molecular geometry is carbon dioxide ( O=C=O).

The molecular formula of a substance does not indicate the shape of the molecule. For example, CO2 is linear but SO2 is an angular molecule. It has been observed that, when atoms combine to form a molecule, pairs of valence electrons arrange themselves in such a way that they appear to be as far as possible from each other. 

Some examples of the shape of molecules whether they are linear molecules or bent molecules or planar molecules.

Molecular geometry means the arrangement of atoms in a molecule. This is usually related to a single central atom. This includes lone pair which helps in predicting the shape of a molecule, however, repulsion in lone pair is considered only in bond angles. For to determine the shape of a molecule, the parameters which are to be taken care of are:

• Bond angles
• Bond length
• Torsional angles 

They influence substance properties such as polarity, color, reactivity or phase of matter. Linear molecules are made up of a central atom that is bonded to two other atoms via a single or double bond. 

Conclusion

Therefore, the above article which talks about the shape of a molecule gives a clear understanding of how the shape of a linear molecule is formed and how the presence of lone pairs makes the shape of the molecule bend. Therefore, if a molecule has a zero lone pair, then it is known as a linear molecule.