To draw the structural formula of ethene, start by sketching two carbon atoms that are interconnected by a double bond. Each carbon atom is also bonded to two hydrogen atoms.

Ethene, also known as ethylene, is a hydrocarbon with the molecular formula $C_2H_4$. It is the simplest member of the alkene family, which is characterized by the presence of double bonds between carbon atoms. To depict the structural formula of ethene, first, draw the two carbon atoms. These atoms are joined by a double bond, represented by two parallel lines. This double bond is the defining feature that classifies ethene as an alkene.

Next, incorporate the hydrogen atoms into your drawing. Each carbon atom in ethene is bonded to two hydrogen atoms. These bonds are single bonds, indicated by a single line. To represent this, draw a line from each carbon atom to a hydrogen atom. In total, there should be four hydrogen atoms, with two attached to each carbon atom.

The completed structural formula of ethene can be expressed as follows:

$H_2C=CH_2$

In this notation, the double bond between the carbon atoms is shown using an equals sign, while the single bonds to the hydrogen atoms are represented by single lines. This formula illustrates that each carbon atom is bonded to one other carbon atom and two hydrogen atoms, fulfilling the four bonds typically associated with carbon.

When drawing structural formulas, it is crucial to illustrate all atoms and bonds clearly. This approach provides a comprehensive view of the molecule’s structure, aiding in the understanding of its properties and chemical reactions. In the case of ethene, the double bond between the carbon atoms is particularly significant, as it imparts unique chemical behaviors characteristic of alkenes.