Answer:
B: circulatory system
Explanation:
The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.
Answer:
See below.
Explanation:
pH = - log (H+)
So the pH of 1 x 10^-7 M solution is 7.
I'm sorry but I'm not sure about what the other units mean, so Im not sure of the answer to those.
If you convert the other units to the form 1 x 10^-n then the pH will be n.
The answer is 3). This is because elements are the simplest form of a substance, and cannot be broken down any further. Compounds on the other hand are much more complex than elements and can be broken down INTO elements.
For example, Na, sodium, is an element and cannot be broken down further. H2O, water, is a compound and can be broken down into Hydrogen and Oxygen.