Question

The number of $\sigma -$and $\pi -$bonds present in $pent-4-ene-1-yne$________is:
A. 10,3
B. 4,9
C. 3,10
D. 9,4

Answer 1

Ethylene has a double bond in between two carbon atoms. One sigma bond and one pi bond. Each carbon has two sigma bonds with two hydrogen atoms as carbon valency is four. So, Ethylene has 5 sigma bonds and 1 pi bond.

Complete step by step answer:
Structure : $HC=C-C{{H}_{2}}-CH=C{{H}_{2}}$
IUPAC Name : $pent-4-en-1-yne$
Triple bond between C and C contains one $\sigma$ bond and two $\pi$ bonds. Double bond between C and C contains one $\sigma$ bond and one $\pi$ bond. Eight $\sigma$ C-H bonds
Total $\sigma$ bonds=10
Total $\pi$ bonds =3

**Hence, the correct option here is A. 10,3

Additional Information: **
1.Generally, all connections between atoms in most natural mixes contain one sigma bond each. In the event that it is a solitary bond, it contains just a sigma bond. Two fold and Triple bonds, notwithstanding, contain sigma and pi bonds. Twofold bonds have one each, and triple bonds having one sigma bond and two pi bonds.
2. Sigma bond is a synthetic bond shaped by the straight or co-pivotal covering of the nuclear orbitals of two particles. A pi bond is a kind of covalent bond that exists between atoms where the electrons are on top and lower part of the pivot associating the cores of the joined molecules.

Note:
sigma bonds are the strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals. Sigma bonding is most simply defined for diatomic molecules using the language and tools of symmetry groups.