Question

A molecule of butane and a molecule of 2-butene both have the same total number of
(1) carbon atoms (3) single bonds
(2) hydrogen atoms (4) double bonds

Answer 1

1) same amount of carbon atoms.

That is why it is still called butane and butene.
but- always signifies 4 carbons

Answer 2

Answer: Option (1) is the correct answer.

Explanation:

A hydrocarbon that contains only single bonds is known as alkane. Their general formula is $C_{n}H_{2n+2}$, where n is the number of carbon atoms.

For example, butane ($CH_{3}CH_{2}CH_{2}CH_{3}$) is an alkane.

Whereas a hydrocarbon that contains at least one double bond is known as an alkene. Their general formula is $C_{n}H_{2n}$.

For example, 2-butene ($CH_{3}CH=CHCH_{3}$) is an alkene.

Hence, there are same number of carbon atoms in both butane and 2-butene.