Question

1. what is the difference between a physical property and a chemical property? give examples of each.
2. explain the difference between elements, compounds, and mixtures.
3. differentiate between homogeneous and heterogeneous mixtures, and give examples.

Explanation:

• Question 4: A physical property is a characteristic of a substance that can be observed or measured without changing the substance's chemical composition. For example, water has a boiling point of \(100^{\circ}C\) (at standard atmospheric pressure), and copper is a shiny, reddish - brown metal. A chemical property is a characteristic of a substance that describes its ability to undergo a chemical change or reaction. For example, iron rusts (reacts with oxygen and water to form iron oxide), and hydrogen gas is flammable (reacts with oxygen in a combustion reaction).
• Question 5: An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom. For example, gold (\(Au\)) is made up of only gold atoms. A compound is a pure substance formed when two or more elements chemically combine in a fixed ratio. For example, water (\(H_2O\)) is a compound made of hydrogen and oxygen in a \(2:1\) ratio. A mixture is a combination of two or more substances (elements, compounds, or both) that are not chemically combined. For example, air is a mixture of nitrogen, oxygen, carbon dioxide, and other gases.
• Question 6: A homogeneous mixture has a uniform composition throughout. For example, a solution of salt in water (the salt is evenly distributed in the water). A heterogeneous mixture has a non - uniform composition. For example, a mixture of sand and water (the sand particles are visible and not evenly distributed in the water).

Answer:

• Question 4: Physical property: observed without chemical change (e.g., water's boiling point). Chemical property: describes chemical change ability (e.g., iron rusting).
• Question 5: Element: one - atom - type pure substance (e.g., gold). Compound: chemically combined elements (e.g., water). Mixture: non - chemically combined substances (e.g., air).
• Question 6: Homogeneous: uniform composition (e.g., salt - water solution). Heterogeneous: non - uniform composition (e.g., sand - water mixture).