3. Matter and Energy

Which element must be present in an organic compound?

In the classification of matter, which element must be present in an organic compound?

In introductory chemistry, organic compounds are defined as compounds that contain which element?

In the context of classifying matter, pencil “lead” is primarily graphite, which is carbon. How should pencil lead be classified?

In the classification of matter, propane (C3H8) is best classified as which of the following?

In the classification of matter, all organic molecules contain which element?

In the classification of matter, which element is present in all organic molecules?

In the context of classifying matter, which element is the primary component of most fossil fuels (coal, petroleum, and natural gas)?

In the classification of matter, baking soda (sodium bicarbonate, $N_{1}aH{C}_1{O}_3$) is best classified as which of the following?

In the classification of matter, how is a compound different from an element?

Which of the following substances is an element?

Classify each of the following pure substances as an element or a compound: b. hydrogen peroxide (H₂O₂)

A compound differs from a mixture because it:

A compound differs from an element in that a compound:

Classify each of the following as an element, a compound, or a mixture: (3.1) b. a salad dressing of oil and vinegar