5. what is the difference between substances and mixtures? give an example of each!
5. what is the difference between substances and mixtures? give an example of each!
Answer
Brief Explanations:
- Substances: Have a fixed, uniform composition (elements or compounds). Elements (e.g., gold, ( \text{Au} )) can’t be broken down chemically. Compounds (e.g., water, ( \text{H}_2\text{O} )) have fixed ratios of elements and can be broken into elements via chemical reactions.
- Mixtures: Combinations of two+ substances (elements/compounds) with variable composition. Homogeneous mixtures (e.g., saltwater) have uniform appearance; heterogeneous mixtures (e.g., sand - water) have distinct phases.
- Examples: Substance (water, ( \text{H}_2\text{O} )); Mixture (air, a mix of ( \text{O}_2 ), ( \text{N}_2 ), ( \text{CO}_2 ), etc.).
Answer:
- Substances: Have a fixed, uniform chemical composition (elements or compounds). Example: Water (( \text{H}_2\text{O} )) (a compound) or gold (( \text{Au} )) (an element).
- Mixtures: Combinations of two or more substances (elements or compounds) with variable composition. Example: Air (a homogeneous mixture of gases) or sand - water (a heterogeneous mixture).