Which object represents a heterogeneous mixture? A. Brass key
B. Metal rings
C. Aluminum pans
D. Steel wool

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Identify and describe the three ways that mutations affect organisms.

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3