The halogens are the elements of group 17 on the periodic table. Halogens combine easily with elements from group 1. When a halogen reacts with a metal, what type of compound is formed?.

After rain, water soaks into the ground and is added to the groundwater. this process is known as a. groundwater pollution. b. groundwater recharge. c. groundwater recycling. d. groundwater filtration.

Can you me find area of the shaded region?

Did the universe cool off or get hotter as it expanded after the 'big bang"?