Question

1. Which gas is a source of natural groundwater pollution?
A. Carbon
B. Oxygen
C. Hydrogen
D. Radon
d?

2. A stream channel is formed when water
A. carves a very deep and wide channel into rock.
B. carries minerals into the ocean.
C. creates a depression, which forms a lake.
D. carves a narrow path into rock.
D?

3. How many chemical reactions are possible regarding the formation of carbonic acid and the dissolving of calcite?
A. 3
B. 10
C. 23
D. 2
a?

Answer 1

right, right, and look it up, I think it is two.

Answer 2

I tried two but its not the correct answer. Could you help me find the right one?

Answer 3

3. How many chemical reactions are possible regarding the formation of carbonic acid and the dissolving of calcite?

A. 3

This is the correct answer. I'm 100 % sure.