Pure Substances and Mixtures

What is a pure substance?

• A material with varying composition and properties

• A mixture of different elements and compounds

• A material that has a constant composition and consistent properties throughout

• A substance that can be easily separated into its components

What is the main characteristic of a homogeneous mixture?

• It appears uniform and consistent throughout.

• It contains multiple phases that are easily distinguishable.

• It has a variable composition that can change over time.

• It is always a solid at room temperature.

Define heterogeneous mixture.

• A mixture that has a uniform composition and cannot be separated, such as saltwater.

• A mixture that has a non-uniform composition, where the different components can be seen and separated, such as salad or sand.

• A mixture that contains only one type of substance, such as pure water.

• A mixture that is always in a gaseous state, such as air.

What is laundry detergent classified as?

• A solution

• A compound

• A mixture

• An element

Can a mixture be a pure substance?

• Yes, a mixture can be a pure substance.

• No, a mixture cannot be a pure substance. Pure substances are either elements or compounds.

• A mixture is always a compound.

• A mixture can be an element.

Give an example of a heterogeneous mixture.

• Fruit salad

• Saltwater

• Air

• Vinegar

What are elements?

• Elements are substances that can be broken down into simpler substances.

• Elements are pure substances that cannot be broken down into simpler substances by chemical means.

• Elements are mixtures of different types of atoms.

• Elements are compounds made of two or more different elements.

What are compounds?

• Compounds are mixtures of two or more elements that can be separated by physical means.

• Compounds are pure substances formed when two or more elements chemically combine in fixed proportions.

• Compounds are elements that have been ionized and can conduct electricity.

• Compounds are substances that can exist in any state of matter without a fixed composition.

What is the difference between a pure substance and a mixture?

• A pure substance has a fixed composition and distinct properties, while a mixture contains two or more substances that retain their individual properties.

• A pure substance can be separated into its components by physical means, while a mixture cannot.

• A pure substance is always a solid, while a mixture can be a solid, liquid, or gas.

• A pure substance is made up of two or more different elements, while a mixture consists of only one type of element.

What is the main characteristic of a heterogeneous mixture?

• Its components can be distinguished and separated.

• It has a uniform composition throughout.

• It is made up of only one type of substance.

• It appears the same throughout under a microscope.