Step 1: Identify the longest continuous chain of carbon atoms in the molecule. In this case, there are 4 carbon atoms.
Step 2: Count the number of carbon atoms. Since there are 4 carbon atoms, the base name will be 'butane'.
Step 3: Determine the presence of a double bond. The formula CH2=CH-CH2-CH3 shows a double bond between the first and second carbon atoms.
Step 4: Since there is a double bond, change the suffix from 'ane' to 'ene'. This gives us 'butene'.
Step 5: Number the carbon chain starting from the end closest to the double bond. The double bond starts at the first carbon, so we label it as 1-butene.
Step 6: Combine the information to write the full IUPAC name: 1-Butene.
