2 shells because if you do the electronic configuration:
2,7 which adds up to 9
7 stands for the group it in and it also stands for how many electrons are in the outer shell.
the amount of spaces stands for which period its in therefore it in period 2
Answer:
The study of movement, distribution and quality of water.
Explanation:
They measure the properties of bodied of water, such as the volume of and stream flow.
Cirrhosis is a disease that affects the liver
