Question

Which statement explains why a molecule of CH4 is nonpolar?

Answer 1

The statement that explains why a molecule of $\text{CH}_4$ is nonpolar is as follows:

$\boxed{\left( 3 \right){\text{ The geometric shape of a C}}{{\text{H}}_4}{\text{ molecule distributes the charge symmetrically}}}$

Further Explanation:

The bonds resulting from the mutual sharing of electrons between the bonded atoms are known as covalent bonds and the compounds that involve these types of bonds are termed as covalent compounds.

Octet Rule

Every chemical element tends to form chemical bonds with other elements in accordance with this rule. The octet rule states that there is a tendency of each element to acquire eight electrons in the valence shell, thereby attaining stable noble gas configurations. Hydrogen is an exception to this rule as it has a maximum tendency to have two electrons, therefore it follows duplet rule.

The atomic number of carbon is 6 and it has a configuration of $1{s^2}2{s^2}2{p^2}$. It requires four electrons to complete its octet. The atomic number of hydrogen is 1 and its electronic configuration is $1{s^1}$. Each carbon requires four electrons to complete its octet so it forms four covalent bonds with four hydrogen atoms and one molecule of $\text{CH}_4$ is formed.

A molecule is said to be nonpolar if it has no electronegativity difference between its bonded atoms and is polar if there exists an electronegativity difference between the atoms.

• If the electronegativity difference between the bonded atoms comes out to be less than 0.4, there is a formation of a nonpolar covalent bond.
• If the electronegativity difference between the bonded atoms is between 0.4 and 1.7, there is a formation of a polar covalent bond.
• If the electronegativity difference between the bonded atoms comes out to be more than 1.7, there is a formation of the ionic bond.

The electronegativity difference between the bonded atoms in $\text{CH}_4$ molecule can be evaluated as follows:

${\text{Electronegativity difference}} = {\text{Electronegativity of C}} - {\text{Electronegativity of H}}$          …… (1)

Substitute 2.5 for the electronegativity of C and 2.1 for the electronegativity of H in equation (1).

$\begin{aligned}{\text{Electronegativity difference}}&= {\text{2}}{\text{.5}} - {\text{2}}{\text{.1}}\\&= {\text{0}}{\text{.4}}\\\end{aligned}$  

The electronegativity difference in $\text{CH}_4$ molecule is 0.4 so the bond is a nonpolar covalent bond.

The molecule of $\text{CH}_4$ is symmetrical in shape so the charge distribution is symmetrical in this molecule and therefore it is a nonpolar molecule (For structure, refer to the attached image).

Learn more:

1. Which is a covalent compound? brainly.com/question/2083444
2. What type of bond exists between phosphorus and chlorine? brainly.com/question/81715

Answer details:

Grade: High School

Chapter: Ionic and covalent compounds

Subject: Chemistry

Keywords: polar, nonpolar, symmetry, CH4, octet rule, electronegativity difference, 0.4, 2.5, 2.1, geometric shape, carbon, hydrogen, 6, 1.

Answer 2

Answer:

The geometric shape of a CH4 molecule distributes the charges symmetrically.

Explanation:

The dipole moment is ruled by the compound's geometry and elements electronegativity difference.

Arranging the forces acording to the elements electronegativity difference withing the molecule geometry will yeld the dipole moment.  

If the forces cancel out, it is a nonpolar compound.

If the forces does not cancel out it is a polar compound.

Picture of such analysis for methane is attached.