Why is chemistry a science but alchemy was not?

Which statement characterizes synthetic polymers? a. they come from animals and plants. b. they are found in nature. c. they are made in a lab. d. they are components of starch.

Use the periodic table to determine how many grams of oxygen would be required to react completely with 859.0 g c2h2

What is the source of continuous heat and energy that we receive from the sun