How can you demonstrate that a piece of chalk has mass?

Asuspension of yeast cells is being grown under anaerobic conditions such that glucose is degraded to ethanol and carbon dioxide. if one wishes to follow this process by monitoring the release of 14co2, at which positions in the glucose molecule would the 14c label need to be incorporated?

The footprints of a dinosaur and the burrow of an ancient shrimp are examples of which kind of fossils

How many formula units in 2.63 mols of nacl?