Most chemical changes in living things cannot take place without what?

When a chemical reaction takes in energy it might feel cold hot boiling electric

The chemical mixture that composes our atmosphere is called

A concrete barrier in a parking lot a structure of mass, frame, or shell? Which one would it be?

What acceleration does the force of earths gravity produce? (a) 9.8 m/s/s (b) It varies depending on how long it has been falling. (c) Gravity does not produce an acceleration. (d) It changes direction every 9.8 meters.

Elements that can conduct electricity are classified as

Zoom all the way in to Daphne Major. Describe its appearance in two sentences.

An alloy contains 56 g of pure silver and 17 g of pure copper. What is the percentage silver in the alloy

Suppose there is 0.63 g of HNO3 per 100 mL of a particular solution. What is the concentration of the HNO3 solution in moles per liter?

Of the three thermodynamic quantities, δg, δh, δs, which is most useful for determining spontaneity of a reaction?

Does the density of an object depend on its size? Explain?.