The question asks to identify the element whose compounds are primarily studied in organic chemistry. This requires recalling the fundamental definition of organic chemistry.
Correct Option: C) Carbon
Organic chemistry is fundamentally defined as the chemistry of carbon compounds. Carbon's unique ability to form four stable covalent bonds and to catenate (form long chains and rings with itself) allows for the vast diversity of organic molecules, which are essential for life and numerous industrial applications.
The question asks for the specific property of carbon atoms that allows them to form diverse structures like long chains, branched chains, and rings by linking with one another. We need to identify the chemical term that describes this unique self-linking ability.
Correct Option: D) Catenation is the unique property of an element to form bonds with atoms of the same element, resulting in long chains, branched chains, or rings. Carbon exhibits this property to the maximum extent among all elements, which is why it forms the backbone of millions of organic compounds.
The question asks for the valency of carbon, which is defined as the number of covalent bonds it can typically form. To determine this, we need to consider carbon's atomic structure and its tendency to achieve a stable electron configuration.
D) Four is the correct answer because carbon has 4 valence electrons and forms 4 covalent bonds to achieve a stable octet configuration.
The question asks for the collective name of compounds that consist solely of carbon and hydrogen atoms. We need to recall the basic definitions of organic chemistry compound classes.
Based on these definitions, only hydrocarbons fit the description of containing exclusively carbon and hydrogen atoms.
C) Hydrocarbons are organic compounds made up of only carbon and hydrogen atoms. This directly matches the definition given in the question.
The question asks to identify the class of hydrocarbons that contain only single covalent bonds between carbon atoms. This requires knowledge of the basic classification of hydrocarbons based on the type of carbon-carbon bonds present.
C) Alkanes are hydrocarbons that contain only single covalent bonds between carbon atoms. Examples include methane (\(CH_4\)), ethane (\(C_3H_6\)), and propane (\(C_3H_8\)).
The question asks to classify hydrocarbons based on the presence of at least one carbon-carbon double bond. This requires knowledge of the basic definitions and classifications of different types of hydrocarbons.
Correct Option: D) Alkenes — Alkenes are unsaturated hydrocarbons characterized by the presence of at least one carbon-carbon double bond (\(C=C\)).