Ahydrocarbon molecule has seven carbon
atoms in a straight chain. there is a double bond
between the third carbon atom and the fourth
carbon atom in the chain. the iupac name for
this hydrocarbon is
(1) 3-heptyne (3) 3-heptene
(2) 4-heptyne (4) 4-heptene

Option (3) is the correct answer.

Explanation:

When a linear chain of carbon and hydrogen atoms is attached by single bonds only then it is known as alkane.

When  a linear chain of carbon and hydrogen atoms contains a double bond then it is known as alkene.

When  a linear chain of carbon and hydrogen atoms contains a triple bond then it is known as alkyne.

Therefore, in the given description there is a double bond between third and fourth carbon. Hence, the IUPAC name of given compound is 3-heptene.

Stated in modern language, Newton's universal law of gravitation states that every particle in the universe attracts every other particle with a force along a line joining them. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.