The collection of which of the following gases involves a catalyst? A)oxygen
B)ammonia
C)carbon dioxide

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?

What element has similar physical and chemical properties as boron.

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.