Answer:
is the isotopic notation of the atom
Explanation:
The isotope notation is:

<em>Where a is the mass number = Number of protons + Number of neutrons</em>
<em>b is atomic number = Number of protons</em>
The atomic number define the nature of the atom, the element with atomic number = 15 is phosphorus, P:

a = 15 protons + 16 neutrons = 31
b = 15
is the isotopic notation of the atom.
Answer:
Hello the answer for the volcanos is here below:
7. Pipe
8. Crater
9. Vent
10. lava flow
11. magma chamber
Hope this helps :)
HI.3H2O. This is the answer