Answer: The new pressure is 3 psi.
Explanation:
Given:
= 12 psi, 
= ?, 
Formula used is as follows.

Thus, we can conclude that the new pressure is 3 psi.
Given :
Number of molecules of
.
To Find :
How many moles are in given number of molecules.
Solution :
We know, in 1 moles of any element/compound contains
at atoms/molecules.
So, number of moles in
molecules are :

Therefore, number of moles are 8.97 .
Answer:
19.K, potassium
Explanation:
it has all properties of metals