Question

Which of the following contains only one type of atom? A) compound C) element B) mixture D) solution

Short answer

C) element

Step-by-step solution

Understanding the Options

First, let's identify what each option means. A compound consists of two or more different types of atoms bonded together. A mixture is a combination of different substances, each retaining its own properties. A solution is a homogeneous mixture where one substance is dissolved in another. An element is a pure substance that cannot be broken down into simpler substances and consists of only one type of atom.

Identifying the Correct Answer

Based on the definitions, an element is the only option that consists of a single type of atom. Compounds, mixtures, and solutions include more than one type of atom.

Conclusion

Thus, the answer to the question is the option that represents a pure substance made entirely of one type of atom, which is the definition of an element.

Key concepts

Elements

Elements are fundamental substances that form the foundation of chemistry. Each element is made of only one kind of atom, and this simplicity is the core of their identity. For instance, oxygen is an element made entirely of oxygen atoms. This distinctiveness is maintained on a periodic table, where elements are organized by their atomic number, representing the number of protons in an atom's nucleus.

Understanding elements is crucial because they are the "building blocks" of all matter. Without these basic substances, the formation of compounds and mixtures wouldn't be possible. In their purest form, elements cannot be broken down into simpler substances and retain distinct properties, such as metallic luster or non-metallic gas.

Compounds

Compounds are fascinating because they result from a chemical combination of two or more different elements. These elements are bonded together in a specific ratio and exhibit properties that differ from their individual components. For example, table salt is a compound made from sodium and chlorine atoms bonded to create sodium chloride.

Compounds always have a fixed, definite arrangement of atoms, which is reflected in their chemical formulas. This consistency ensures that a compound like water ( H_2O ) is always made up of two hydrogen atoms and one oxygen atom. In breaking down compounds into their elemental components, chemical reactions are necessary. This highlights the strength of their atomic bonds, unlike mixtures, which can be separated physically.

Mixtures

Mixtures are unique because they involve two or more substances combined physically, not chemically. Each component in a mixture retains its original properties, making it possible to separate them through physical means like filtration or evaporation. An example of a mixture is a salad, where each ingredient keeps its identity.

Mixtures can be categorized as either homogeneous or heterogeneous. Homogeneous mixtures have uniform composition throughout, such as saltwater, while heterogeneous mixtures like oil and water do not mix uniformly. This variability underscores the non-binding nature of the substances involved in mixtures.

Solutions

Solutions are a special type of mixture where substances are distributed evenly at the molecular level. In a solution, one substance is dissolved in another, forming a homogeneous mixture. For example, when you dissolve sugar in water, the result is a solution.

Solutions have two main components: the solute, which is the substance being dissolved, and the solvent, which is the substance doing the dissolving. Solutions are characterized by their uniform appearance and consistent properties throughout. This even distribution makes solutions distinct from other mixtures, as they require typically at least a portion of a chemical process to create.