A sample of an unknown substance has a mass of 42g and a volume of 28 cm3. What is the density of the substance?

All cells are made of four types of acids, lipids, proteins, and carbohydrates.

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory