The structures of four organic compounds are shown below. Which statement is not correct? A. Only one of the compounds is an alcohol.
B. Only one of the compounds is an alkane .
C. Only one of the compounds is unsaturated
D. Only three of the compounds are hydrocarbons.

Option B. Only one of the compounds is an alkane

Explanation:

To know which option is wrong us, we simply determine the class to which each diagram belongs.

Diagram 1:

CH4 is called methane and it is a member of the alkane series which are saturated hydrocarbon.

Diagram 2:

CH3CH3 is called ethane and it is a member of the alkane series which are saturated hydrocarbon.

Diameter 3:

CH2=CH2 is called ethene and it is a member alkene series which are unsaturated hydrocarbon.

Diagram 4:

CH3CH2OH is called ethanol which is a member of the alcohol family. CH3CH2OH is also a saturated alcohol as it only contains single bonds.

From the above, we can see that:

1. Only one compound is alcohol i.e CH3CH2OH.

2. There are two members of the alkane series i.e CH4 and CH3CH3.

3. Only one compound is unsaturated i.e CH2=CH2. Unsaturated compound has one or more double bond.

4. Only three compounds are hydrocarbon i.e CH4, CH3CH3 and CH2=CH2. Hydrocarbons are compounds containg only carbon and hydrogen.

Therefore, option B is wrong as there are two members of the alkane present.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

it's all four options.