Compounds are formed as a result of a chemical change between elements. How should this statement be evaluated?

Introduction / Context:
Elements combine to form compounds through chemical reactions that involve making and breaking of chemical bonds. This process is fundamentally different from forming a physical mixture, where substances retain their individual properties. The statement in the question says that compounds are formed as a result of a chemical change, and this needs to be judged as correct or incorrect based on basic definitions from introductory chemistry.

Given Data / Assumptions:

• A chemical change involves transformation of substances into new substances with different properties and compositions.
• Compounds are substances composed of two or more elements in fixed proportions by mass.
• Physical mixtures do not involve chemical bonding changes and can often be separated by simple physical methods.
• Nuclear changes affect atomic nuclei and are not part of ordinary chemical compound formation.

Concept / Approach:
A compound is defined as a pure substance made up of atoms of two or more different elements chemically combined in a fixed ratio. Examples include water, sodium chloride and carbon dioxide. To form a compound, a chemical reaction must occur in which bonds are formed between atoms, changing their original identities as separate elements. This is clearly a chemical change because the original elements cannot be recovered by simple physical processes without reversing the chemical reaction. The statement that compounds are formed as a result of a chemical change is therefore aligned with the standard definition and should be considered correct.

Step-by-Step Solution:
Step 1: Recall the definition of a compound as a pure substance formed when two or more elements chemically combine in fixed proportions. Step 2: Recall the definition of a chemical change as a process in which one or more substances are transformed into new substances with different chemical compositions. Step 3: Recognise that when hydrogen and oxygen react to form water, or sodium and chlorine react to form sodium chloride, new substances with different properties are created, which is a chemical change. Step 4: Understand that in these examples the original elements are no longer present as separate substances; they are now part of a new compound. Step 5: Conclude that the statement compounds are formed as a result of chemical change accurately describes how compounds come into existence.

Verification / Alternative check:
Think about separating a compound into its elements. Water can be broken down into hydrogen and oxygen only by electrolysing it or other chemical means, not by simple filtering or distillation that separate mixtures. Sodium chloride can be decomposed into sodium and chlorine by electrolysis of molten salt, which is again a chemical change. These facts confirm that compounds are created and destroyed by chemical changes, not by merely rearranging substances physically. Therefore, the statement is fully consistent with the way compounds behave and are defined in chemistry.

Why Other Options Are Wrong:
- Incorrect statement, compounds are only physical mixtures of elements: This contradicts the definition of compounds, which involve chemical bonding and cannot be separated by simple physical processes.
- Correct only for ionic compounds, not for covalent compounds: Both ionic and covalent compounds are formed by chemical reactions and involve changes in bonding, so the statement applies to both.
- Correct only for organic compounds, not for inorganic compounds: The distinction between organic and inorganic compounds does not affect how they are formed; both arise from chemical changes between elements.
- Incorrect, compounds are formed by changes in nuclear structure only: Nuclear changes produce different elements or isotopes, not chemical compounds in the usual sense.

Common Pitfalls:
Students sometimes confuse mixtures and compounds, especially when two substances appear uniform together. For example, air is a mixture of gases, not a compound, because its components can be separated physically and do not react chemically to form a single new substance. Another confusion is to think of any change of state as a chemical change, when melting or boiling water are physical changes because the composition H2O remains the same. Compounds require the making or breaking of bonds, which is the hallmark of chemical change described correctly in the statement.

Final Answer:
The statement is Correct, because compounds are formed when elements undergo a chemical change and chemically combine.