How many atoms of oxygen are in seven molecules of lead (II) nitrate? A) 7
B) 6
C) 42
D) 3

How does chemistry affect our world? a. chemicals makes our world more polluted. b. chemicals keeps us healthy. c. chemicals can or hurt our world. d. chemicals make our world safe to live in.

In which region is the substance in both the solid phase and the liquid phase? 1 2. 3 4 mark this and return save and exit next

What is the most common reason for matter changing its state?