Which molecule is most likely to contain only single covalent bond?

a)co2
b)HCN
c)CH4
d)H2ccH2

Think about c.

Well, I must say, all molecules are quite the "bonding" experience! But in this case, the molecule that is most likely to contain only a single covalent bond is "c) CH4," also known as Methane. It's a molecule that keeps it simple with just one single bond between each carbon and hydrogen atom. It's like a minimalist molecule, you know?

The molecule that is most likely to contain only single covalent bonds is (c) CH4, which stands for methane.

To determine which molecule is most likely to contain only a single covalent bond, we need to examine the chemical composition and bonding patterns of the given options.

Covalent bonds occur when atoms share electrons to form a stable arrangement. Single covalent bonds involve the sharing of one pair of electrons between two atoms. With this in mind, let's analyze the options:

a) CO2:
Carbon dioxide (CO2) consists of two oxygen atoms bonded to a central carbon atom. The carbon-oxygen bonds in CO2 are double covalent bonds, not single covalent bonds. Therefore, option a) is not the correct answer.

b) HCN:
Hydrogen cyanide (HCN) is composed of a hydrogen atom bonded to a carbon atom, which, in turn, is bonded to a nitrogen atom. Both the carbon-hydrogen bond and the carbon-nitrogen bond in HCN are single covalent bonds. Thus, option b) is a possible correct answer.

c) CH4:
Methane (CH4) consists of one carbon atom bonded to four hydrogen atoms. In CH4, all the carbon-hydrogen bonds are single covalent bonds. Therefore, option c) is a possible correct answer.

d) H2CC H2:
This molecule is known as "allene" and is structured with two carbon atoms. Between each carbon atom, there are two double covalent bonds and one single covalent bond. This means that H2CC H2 doesn't contain only single covalent bonds. Thus, option d) is not the correct answer.

Considering the analysis above, options b) HCN and c) CH4 both contain only single covalent bonds. However, it's important to note that a molecule can have multiple single covalent bonds, as seen with CH4.

Therefore, the answer is: both b) HCN and c) CH4.